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 فعالیت بدنی و پیشگیری از دیابت نوع دوم

Physical Activity and the
Prevention of Type II
(Non–Insul in-Dependent ) Di abet es
An drea Kri ska
UNI VERS ITY OF PIT TSBU RGH
ORIGINALLY PUBLISHED AS SERIES 2, NUMBER 10, OF THE PCPFS RESEARCH DIGEST.
HI GHLI GHT
“T here is a st ron g li nk be t wee n t y pe II di a bet es a n d se dent a ry
li ving. Th e bi ggest be nefi t s a p pea r t o be fo und a m on g t h ose wh o
in corp ora t e so m e le vel of re gu la r p h ysic a l a c t ivi t y in t o t h eir
d a ily li ves. Ph ysic a l a c t ivi t y, a s re com m en d e d by t h e Su rgeo n
Ge nera l, wo uld se em t o be a pr uden t st ra t e gy fo r a l l pe op le ,
esp eci a lly t h ose wh o a r e a t ri sk fo r t y p e II d i a bet es.”
A NOTE FRO M TH E ED ITOR S
According to the Surgeon General’s report, as many as 8 million Americans know they have
diabetes and at least 8 million more have diabetes but do not know it. More than 150,000
deaths each year are attributed to this condition. We asked Dr. Andrea Kriska, a researcher
who studies diabetes, to write about this physical activity association.
There are two general classes of diabetes. As noted in the Surgeon General’s Report,
diabetes is a group of disorders that are associated with high blood sugar levels. “Insulin-
dependent diabetes mellitus (IDDM or type I) is characterized by an absolute deficiency of
circulating insulin...(page 125).” Non–insulin-dependent diabetes mellitus (NIDDM, or ty pe
II ) is ch aracterized by “ elevated in sulin levels th at ar e in effective in no rmalizin g...
blood su gar levels... or by im paired in sulin secretion (p age 12 5).” Because mo st cases
of diabetes are of th e second ty pe (type II) an d because ph ysical activity has been sh own
to be mo re related to th is ty pe of disease, we have asked Dr. Kriska to fo cus on ty pe II
diabetes. In th is paper, many qu estions ab out diabetes are an swered an d tables
su mmarize key po ints. A list of basic definition s of key terms used in th e paper is
presen ted in Figure 11 .1.
FIGURE 11. 1
Ba sic de fin i tion s of k e y te r m s.
In suli n. A hormone secreted by the pan creas th at regul ates lev els of s ugar in the bloo d.

In suli n Re sist ance . A con diti on t hat occurs when insulin beco mes ineffect ive or l ess effectiv e th an i s
ne cess ary to r egul ate suga r le vels in the bloo d.
In sulin Se nsit ivit y. A person with ins ulin res istance (see abo ve) is s aid to h ave decreased in suli n
se nsit ivit y. T he b ody’ s ce lls are not sens itiv e to ins ulin so they res ist it and s ugar lev els are not regulated
effect ivel y.
Di abetes. A gro up o f di sorders that res ults in too much sug ar i n th e bl ood, eit her because the body does
no t make enoug h in suli n or mak es i nsul in b ut canno t properly use i t.
Oral Gluco se Tolerance Test. A tes t to det ermi ne i f a pers on i s di abet ic. The test measures th e
bo dy’s abi lity to clear sugar from the blo od i n a reas onab le t ime afte r ha ving tak en a sta ndar dize d or al d ose
of glu cose (su gar) .
Bl ood Glucose. Sugar lev els in t he b lood.
WHAT IS TYPE II DIABET ES?
Diabetes can be defined simply and succinctly as “too much glucose in the blood” (West,
1978). It is a devastating disease that can often lead to complications such as blindness,
kidney failure, coronary heart disease, circulatory problems that may result in amputation,
nerve problems, and premature death.
Among those with diabetes, type II is the most common type, accounting for 90–95% of
all diabetic cases and affecting about 7% of the US population (DIA; Harris, 1987). Among
those with type II diabetes, most (60–90%) but not all are obese when the disease is diagnosed
(National Diabetes Data Group, 1979). Symptoms that are usually associated with the onset of
type II diabetes are the direct result of the high blood glucose, although in many milder cases
of diabetes, there may not be any symptoms (West, 1978). In fact, it has been estimated that
the number of individuals in the general population who are not aware that they have type II
diabetes is equal to the number of individuals who have been diagnosed with the disease
(Harris, 1995).
Just as hypertension is diagnosed at the upper end of a blood pressure distribution, the
diagnosis of diabetes is usually made at the upper end of a continuum of blood glucose
values. Typically, the diagnosis of type II diabetes is determined based upon a specific test
administered in a fasting state (an oral glucose tolerance test) in which the blood glucose
values are measured two hours after drinking a specific glucose solution (WHO, 1980). An
individual is considered to have diabetes if the blood glucose values two hours after drinking
the mixture are 11.1 mmol/l or greater. Just as someone with borderline blood pressure values
are at high risk for hypertension, an individual is considered to be at risk for diabetes if
his/her blood glucose values two hours after drinking the solution are 7.8–11.0 mmol/l, which
is called impaired glucose tolerance (WHO, 1980).

Despite the fact that type II diabetes is a complex condition caused by both genetic and
behavioral factors, the basic metabolic abnormalities responsible for the high blood glucose
values are resistance of the body’s cells to the action of insulin (termed insulin resistance or
decreased insulin sensitivity) and the inability of the pancreas to secrete enough insulin to
meet the glucose demand (termed insulin deficiency). During the early stages of the disease
development in a genetically prone individual, insulin resistance of the insulin-sensitive tissues
of the body (muscles and liver) can usually be found (DeFronzo, 1992). Being insulin
resistant means that the glucose cannot readily enter the cells, resulting in a rise of blood
glucose concentrations. This increase in blood glucose causes the pancreas to secrete more
insulin in an attempt to normalize the blood glucose levels. If allowed to continue, this cycle
of resistance and secretion proceeds until the amount of insulin that is secreted is no longer
sufficient to compensate for an extreme amount of tissue insulin resistance, resulting in
elevated blood glucose values and eventually diabetes (Saad, 1988; Knowler, 1995).
WH AT IS TH E PH YSIO LOGICAL BASIS BEHIND A
PO TENT IAL RELA TION SHIP BETWEEN PHYSICA L
ACTIVITY AND THE PREVENTION OF TYPE II
DI ABET ES?
Various reviews of the effects of physical activity on insulin resistance and glucose tolerance
have identified the physiological reasons why a relationship between physical activity and
type II diabetes is possible (Vranic, 1979; Bj.rntorp, 1985; Koivisto, 1986; Lampman, 1991;
Horton, 1991; Wallberg-Henriksson, 1992; Zierath, 1992). In general, active individuals have
better insulin and glucose profiles than their inactive counterparts (Stevenson, 1995;
Lohmann, 1978) with detraining and bed rest shown to deteriorate these metabolic parameters
(Lipmann, 1972; Heath, 1983). Equally as convincing, exercise training studies have found
physical activity to improve insulin action or, in other words, decrease insulin resistance
(Saltin, 1979; Lindg.rde, 1983; Krotkiewski, 1983; Trovati, 1984; Schneider, 1984; Seals,
1984; R.nnemaa, 1986). Less consistently, some exercise training studies have also found
activity to improve glucose metabolism in both normal individuals and those with mild type II
diabetes (Minuk, 1981; Holloszy, 1986). Based upon the findings of these training studies, it
appears that physical activity would most likely impact on insulin action in individuals at high
risk for diabetes (with hyperinsulinemia), that is, those individuals whose capacity to secrete
insulin is still intact and insulin resistance is the major cause of the abnormal glucose
tolerance (Holloszy, 1986).
Obesity and fat distribution (specifically, the distribution of body fat in the central as
compared to the peripheral regions) are major contributors to insulin resistance and are
therefore, strongly involved in the pathogenesis of type II diabetes (Bj.rntorp, 1988;
Bj.rntorp, 1991; Dowse, 1991; Haffner, 1986; Hartz, 1983; Kissebah, 1989; Knowler, 1991;
Modan, 1986; Ohlson, 1985; Stern, 1991). Physical activity has also been shown to be
inversely associated with obesity and central fat distribution, with studies demonstrating that
physical training can reduce both of these parameters (Bj.rntorp, 1979; Brownell, 1980;
Despres, 1988; Krotkiewski, 1988). In other words, it is feasible that physical activity may also
prevent or delay type II diabetes through decreasing overall fat and/or intra-abdominal fat.

In summary, it appears that physical activity may not only be related to type II diabetes
directly but also indirectly through obesity. Since most individuals with type II diabetes are
obese, and change in activity is often associated with small but important changes in fat and
body composition, complete separation of the effects of activity from the effects of body
composition on type II diabetes is often difficult (Schwartz, 1997). However, clinical studies
examining the effects of physical training on patients with type II diabetes have suggested a
direct relationship between the two, independent of obesity.
FIGURE 11. 2
Possible mechanisms through which physical activity may prevent or delay
the development of type II diabetes.
n Decrease i nsul in resis tance/improv e in suli n sensit ivit y
n Im prov e bl ood gluc ose leve ls ( gluc ose tole ranc e)
n De crea se o vera ll a dipo sity
n Reduce cen tral adi posi ty
n Desirable chan ges in muscl e ti ssue
DO EPIDEMIOLOGY ST UDIES SU PPOR T A
RELATI ONSHIP BETWEEN PHYSI CAL ACTI VITY AND
TYPE II DIABET ES?
Through the years, from early observations to current epidemiological studies, support for the
existence of a relationship between physical activity and type II diabetes has been increasing.
Suggestions of a relationship between physical activity and type II diabetes were supported
early on by the fact that societies that had abandoned traditional lifestyles (which typically
had included large amounts of habitual physical activity) had experienced major increases in
type II diabetes (West, 1978). Indirect evidence of this phenomenon was also provided by the
observation that groups of subjects who migrated to a more modern environment had more
diabetes than their ethnic counterparts who remained in their native land (Hara, 1983; Kawate,
1979; Ravussin, 1994) or that rural dwellers had a lower prevalence of diabetes than their
urban counterparts (Cruz-vidal, 1979; Zimmet, 1981; Zimmet, 1983; King, 1984). In these
studies, differences in physical activity were suggested as partial explanations for the
differences in diabetes prevalence. Results of epidemiology studies are described in the
following sections and summarized in Figure 11.3.
FIGURE 11. 3
Ep idem iolo g ica l st u die s su p p or tin g th e r e lati on sh ip b e twee n p h y sic al
ac tiv i ty an d ty p e I I di ab et es.
Cross- sect ional St udy: B oth diab etes sta tus (and glu cose /ins ulin lev els) and phy sica l ac tivi ty l evel s
ar e de term ined at the same poi nt i n ti me i n th e sa me i ndiv idua ls.
n In divi dual s wi th t ype II diabetes are less act ive than tho se witho ut diabetes.

.
Among thos e wi thout ty pe II di abet es, more act ive indi viduals have lower g luco se and i nsul in v alues
th an t heir inactiv e co unterparts.
Ca se-C ontrol ( or R etro spec ti ve ) St udy : I ndiv idua ls w ith and with out type II diab etes are ask ed
questi ons about th eir past , in thi s case, thei r ph ysical activ ity levels.
.
In divi dual s wi th t ype II diabetes repo rted les s ph ysical activ ity over their l ifet ime than individuals
wi thout di abet es.
Pr ospe ctiv e or Lo n gitu di na l St udy : Inact ive and acti ve i ndiv iduals witho ut t ype II diabetes are
fo llowed o ver time to determin e if phy sical activi ty l evel s pl ay a rol e in det ermi ning who wil l an d wi ll n ot
develo p th e di seas e.
.
Wo men alum nae who were for mer coll ege athl etes had a l ower pre vale nce of d iabe tes than tho se w ho
were n onat hlet es.
.
Fo r men an d wo men alik e, i ndiv iduals who are relat ivel y mo re p hysi call y active are les s li kely to
develo p ty pe II di abet es i n th e future than th ose who are sedentary.
Ex peri ment al S tudy o r Cl i n i cal Tri al : I ndiv idua ls f ree of t ype II d iabe tes are rand omly ass igne d to
a group th at i ncludes a ph ysical activ ity prog ram or does not incl ude it. Foll ow-up of these g roup s ov er
ti me w ill exam ine whic h gr oup deve lops mor e di abet es i n th e fu ture .
.
In divi dual s as sign ed t o th e group that includes a phys ical act ivit y program develo ped less diabetes
ov er t ime than tho se who were not assi gned to the acti vity gro up.
Cross-sectional studies collect information about the health outcome (glucose intolerance
or type II diabetes) and the potential risk factor (physical inactivity) at the same time within
the same group. This type of epidemiological design is limited because it is not possible to
establish causality; i.e., did inactivity cause the glucose intolerance or did the condition cause
the inactivity.
Cross-sectional epidemiological studies have shown that physical inactivity was associated
with type II diabetes and glucose intolerance within populations. Groups of subjects with type
II diabetes were found to be less active currently (Taylor, 1983; Taylor, 1984; King, 1984;
Dowse, 1990; Ramaiya, 1991; Kriska, 1993) than nondiabetic persons. In addition, cross-
sectional studies that have examined the relationship between physical activity and glucose
intolerance in individuals without type II diabetes generally showed that blood glucose values
after an oral glucose tolerance test (Lindg.rde, 1981; Cederholm, 1985; Wang, 1989;
Schranz, 1991; Dowse, 1991; Kriska, 1993; Periera, 1995) as well as insulin values
(Lindg.rde, 1981; Wang, 1989; Dowse, 1991; McKeigue, 1992; Feskens, 1994; Regensteiner,
1995) were significantly higher in the less active compared to the more active individuals.
In case-control (or retrospective) study designs, individuals with and without diabetes
are asked questions about their past, particularly their exposure to the specific risk factor in
question (i.e., physical activity level). Although this type of study design is valuable in cases
where the disease outcome is rare, it does suffer from potential recall bias, in which the
diseased or high-risk individual may remember or recall past events differently. An example
of this type of study design was demonstrated in the Pima Indian Study in which those
individuals from the Gila River Indian Community with diabetes reported less physical
activity over their lifetime than individuals without diabetes (Kriska, 1993).
The most powerful observational study design is the prospective or longitudinal study
design. This particular design identifies and follows individuals initially free of the health
outcome of interest (diabetes) and seeks to establish if initial or subsequent physical activity
levels differentiate those who do and do not develop the disease.

The fact that a sedentary lifestyle may play a role in the development of type II diabetes
has been demonstrated in prospective studies of college alumni, registered nurses, physicians,
and middle-aged British men (Helmrich, 1991; Manson, 1991, 1992; Perry, 1995). Women
alumnae who were former college athletes had a lower prevalence of diabetes than those who
were nonathletes (Frisch, 1986). A study of male alumni from the University of Pennsylvania
(Helmrich, 1991) demonstrated that physical activity was inversely related to the incidence of
type II diabetes, a relationship that was particularly evident in men at high risk for developing
diabetes (defined as those with a high body mass index, a history of hypertension, or a
parental history of diabetes). In a study of female registered nurses aged 34–59 years, women
who reported engaging in vigorous exercise at least once a week had a lower incidence of
self-reported type II diabetes during the eight years of follow-up than women who did not
exercise weekly (Manson, 1991). Similar findings were observed between exercise and
incidence of type II diabetes in a five-year prospective study of 40–84-year-old male
physicians (Manson, 1992). Finally, the risk of developing diabetes over a 13-year period was
reduced by 50% in men engaged in moderate to vigorous levels of physical activity
compared to the less active men (Perry, 1995). Although the results of all of these prospective
epidemiological studies suggest a causal relationship between physical inactivity and type II
diabetes, the strength of their findings is weakened due to the determination of diabetes based
upon self-report rather than an oral glucose tolerance test (since an estimated 50% of the
general population are not aware that they have type II diabetes).
Similar to measures of physical activity, physical fitness as determined by maximal
oxygen uptake or as estimated by vital capacity also appears to play a role in the development
of type II diabetes (Eriksson, 1996, 1991). In addition, support that physical fitness may
provide some protection against mortality in men at all levels of glucose intolerance (from
those with normal blood glucose to those with type II diabetes) was demonstrated in middle-
aged men (Kohl, 1992).
Physical activity was a major part of the intervention strategy of a feasibility trial of
diabetes prevention in 47–49-year-old men from Malmo, Sweden. Of those with impaired
glucose intolerance at baseline, at least twice as many of those who did not take part in the
treatment program had developed diabetes at the five-year follow-up compared with those
who participated (Eriksson, 1991). However, since the participants were not randomly
assigned to the intervention treatment groups, and since the treatment groups differed by
medical condition at baseline, the results of this study are not conclusive. In other words, the
hypothesis that physical activity intervention may prevent type II diabetes was not adequately
tested.
The most powerful and by far the most labor-intensive epidemiological study design is
the experimental design or clinical trial in which efforts are made to prevent or delay the
onset of the type II diabetes by manipulating the risk factor of interest, in this case, physical
activity levels. In this design, individuals free of type II diabetes would be randomly assigned
to receive either the intervention (the physical activity intervention group) or no intervention
(the control group). Subsequent follow-up of the two groups over time would determine if
the groups differ by the percent who eventually develop the disease outcome.

Results of a more recent clinical trial demonstrated that physical activity intervention led
to a decrease in the incidence of diabetes over a six-year period among Chinese individuals
initially identified with impaired glucose tolerance (Pan, 1997). At the beginning of the study,
577 individuals with impaired glucose tolerance were identified from a citywide health
screening in DaQing and randomized by clinic into one of four groups: exercise only, diet
only, diet plus exercise and a control group. Individuals assigned to the exercise group were
encouraged to increase their daily leisure physical activity to that comparable to a 30-minute
walk. The percent that developed diabetes was significantly lower in each of the three
intervention groups compared to the control group (exercise = 44%, diet = 47%, exercise
plus diet = 44%, control = 66%).
An example of a randomized, multi-center clinical trial of type II diabetes prevention that
incorporates physical activity as one of the possible treatments is currently underway in the
United States (Diabetes Prevention Program, sponsored by the National Institutes of Health;
NIH, 1993). In this trial, physical activity is combined with dietary modification to comprise
the lifestyle intervention arm of the study. Anyone interested in participating in the Diabetes
Prevention Program and/or wants to obtain more information about the program should call
the following toll-free number (1-888-DDP-JOIN).
PH YSICAL A CTIVITY RECO MMEN DATIONS: HOW
MUCH IS EN OUGH?
Recent national physical activity recommendations and summary statements suggest that the
majority of overall health benefits from physical activity are gained by performing activities
that are not necessarily of high intensity (Pate, 1995). In fact, it has been suggested that the
sedentary individual who begins to incorporate adequate amounts of moderate levels of
physical activity into his/her lifestyle such as walking and gardening may attain substantial
health benefits and reduce cardiovascular disease risk (Pate, 1995). How can we best
incorporate physical activity into our lifestyle to maximize the health benefits specific to type
II diabetes?
Ty pe of Ph y sical A ctiv ity Recom m en ded
Most of the exercise training and epidemiology studies done to date have focused on aerobic
types of activity that require the use of large muscle mass such as walking, running, and
biking. Aerobic activities are recommended for the overall public as the primary type of
activity because of their potential benefits in regards to improving the type II diabetes and
cardiovascular risk profile (Surgeon General’s Report, 1996).
Recently, the benefits of incorporating strength training into an overall activity regimen
(that includes aerobic activity) for the prevention and treatment of type II diabetes are being
recognized. Strength training has been shown to acutely improve glucose tolerance and
insulin sensitivity in individuals with both normal and abnormal glucose tolerance (Smutok,
1994; Miller, 1994).

Fr eque ncy/ Du r a tion of Phys ical Act iv it y Re com m en de d
A substantial part of the improvements in glucose tolerance and insulin resistance due to
exercise are believed to be the result of the cumulative effect of a frequent lowering of the
blood glucose levels and decreasing insulin resistance with each specific bout of exercise
(Schneider, 1984). In fact, it appears that a large portion of the effect of exercise in
decreasing insulin resistance is short-lived, lasting for a few days, whereas the blood glucose
lowering effect of activity may not even last that long (Heath, 1983; Koivisto, 1986). Possible
additional improvements in glucose tolerance and insulin resistance due to a training effect of
regular exercise on these parameters have been suggested as well (Young, 1989).
In addition, the adaptation caused by increased levels of physical activity that can have an
impact on insulin resistance over the long term (especially in the older adult) is the change in
body composition. This is in light of the fact that a very critical individual goal in regards to
glucose intolerance is to attain and maintain an appropriate weight. Physical activity, in
conjunction with diet, appears to be the best combination for decreasing weight
(preferentially decreasing centrally distributed fat) and to improving glucose tolerance and
insulin sensitivity (Yamanouchi, 1995). Furthermore, physical activity has been shown to play
an important role in long-term weight maintenance (Wing, 1988; Pavlou, 1989).
Based upon the information provided above, at what frequency should one attempt
exercise throughout the week? Since one of the goals for incorporating physical activity into
one’s lifestyle is to “burn more calories,” and since a substantial portion of the improvement
in insulin and glucose appears to be short-lived, it seems reasonable to recommend a
frequency of exercise of several times per week. In other words, the weekend exerciser should
strongly consider adding a few extra bouts of physical activity throughout the week to
maximize his/her benefits in regards to glucose tolerance and insulin sensitivity (not to
mention the fact that it is safer from a cardiovascular risk point of view).
In tens ity of Physical Activity Recom m e nded
In regards to insulin sensitivity and glucose tolerance, physical training studies suggest that
higher intensity exercises are more likely to bring about the desired metabolic changes than
lower intensity activities (Holloszy, 1986; Seals, 1984). Lower intensity activities appear to
follow in the same general direction, although the onset of the effects are much slower and
less dramatic (Bj.rntorp, 1995).
In regards to caloric expenditure, intensity of activity is not an issue. The important thing
is that activity is being done! In general, lower intensity activities are usually easier to adopt in
one’s lifestyle and are relatively less likely to result in injury (Pollock, 1991). It is
recommended that beginners start any physical activity slowly and gradually speed up the
pace and build up the duration over time.
Finally, it appears that the largest and most consistent difference in risk of type II diabetes
occurs between those individuals who report relatively no activity and those who report doing
something (see the review by Kriska, 1994). This would suggest that the individuals who
would benefit the most from any public health effort to prevent type II diabetes would be the
sedentary individuals. If you are currently sedentary, or know people who do not incorporate
activity into their lifestyle with any regularity, now is the time, and here is the reason, to begin
to incorporate moderate levels of physical activity such as walking and gardening. If you
have diabetes or coronary heart disease, it is suggested that you talk with your physician
before increasing your activity level (ADA Council on Exercise, 1990; Schwartz, 1997). If
you are already active, keep up the good work.

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فعالیت جسمی و پیشگیری ديابت نوع دوم

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نکته های مهم : یک اتصال قوی بین ديابت نوع دوم  و زندگی ثانویه ست.

بیشترین فواید زمانی بدست می اید که سطح منظم فعالیت جسمی را در زندگی های روزمره به کار بریم. فعالیت جسمی بوسیله جراح عمومی توصیه می شود .به نظر می رسد استراتژی محتاتی برای همه افراد به ویژه آنها که در معرض خطر بیماری دیابت نوع دوم هستند.

یک نکته (یادداشت) از نویسندگان :

   بر طبق گزارش کلی جراح ، 8 میلیون آمریکایی می دانند که بیماری دیابت دارند و حد اقل 8 میلیون به بالا نمی دانند که بیماری دیابت دارند.  هرساله بیش از 150000 مرگ بر اثر این شرایط رخ می دهد. از دکتر اندرو کرسیکا که تحقیقی در زمینه دیابت داشته برای نوشتن در باره این انجمن فعالیتی جسمی سوال کردیم.

   دو کلاس عمومی دیابت وجود دارند . بر اساس گزارش کلی جراح ، افراد دیابتی گروهی هستند که سطح قند خون بالا دارند و انسولین به این بیماران دیابتی توصیه می شود. انسولین کمک می کند که سطح قند خون عادی شود یا به بدن ضرر نرساند. زیرا بیشتر دیابتی ها از نوع دوم هستند ، به خاطر فعالیت جسمی نشان داده شده مربوط به این بیماری هستند. از دکتر کریسکا برای تمرکز روی دیابت نوع دوم سوال کردیم. در این مقاله سوالات زیادی درباره دیابتی ها پاسخ داده شده است و در جدول ها نکته های کلیدی خلاصه نویسی سده است . فهرستی از تعاریف ، اصطلاحات کلیدی اساسی در این مقاله  11.1 آورده شده است.

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 دیابت نوع دوم چه نوع بیماری است ؟

   دیابت به شکل ساده و مختصر این گونه تعریف شده است: قند خیلی زیاد در خون. ( اواسط سال 1978 ) ، بیماری محرنی است که می تواند منجر به نابینایی ، نارسایی کلیه ، اشداد شرایین قلب ، مشکلات شایع که گاه منجر به قطع عضو می شود ، مشکلات عصبی و مرگ زود هنگام می شود.

   در میان دیابتی ها ، نوع دوم شایع ترین است . 90 تا 95 درصد موارد دیابتی داریم که 7 درصد مربوط به جمعیت آمریکا است. در میان دیابت نوع دوم بیشتر از 60 تا 90  درصد  اما همه آنها چاق نیستند که بتوان بیماری را تشخیص داد.  علائمی که معمولا با دیابت نوع دوم همراه است ، قند خون بالاست. اگر چه در موارد ملایم تر دیابت ممکن است علائمی هم نباشد.

   در حقیقت  تخمینی که زده اند در مورد افرادی است  که از دیابت نوع دوم  اگاه نبوده اند .  فشار خون فقط به واسطه فشار خون بالا  تشخیص داده می شود . تشخیص دیابت معمولا از بالا بودن قند خون مشخص می شود . به طور معمول تشخیص دیابت نوع دوم به وسیله تست مخصوص انجام می شود ، که قند خون 2 ساعت بعد از نوشیدن محلول گلوکز خاص توسط سازمان بهداشت جهانی  1980 اندازه گیری شد.

   یک فرد دارای دیابت است اگر قند خون ، 2 ساعت بعد از نوشیدن 11.1  یا بیشتر باشد ، فقط کسی که فشار خون لب مرز دارد خطر فشار خون بالا را دارد.

  یک فرد خطر ابتلا به بیماری دیابت را دارد اگر قند خونش 2  ساعت بعد از نوشیدن محلول  11 – 7.8  باشد که قدرت تحمل گلوکز را ندارد.

   علی رغم این حقیقت که دیابت نوع دوم ژنتیکی و تحت عوامل رفتار است نا به هنجاری متابولیسم برای قند خون بالا موثر است و سلول های بدن نیاز به انسولین دارند. و نارسایی پانکراس ، انسولین  کافی را برای تقاضای گلو کز دارد . بودن انسولین به این معناست که گلوکز نمیتواند داخل سلول شود . در نتیجه افزایش قند خون را داریم. این افزایش قند خون باعث می شود که پانکراس بیشتر انسولین را در سطح قند خون بالا مخفی کند.

   رقابت بالقوه بین فعالیت جسمی و پیشگیری از دیابت نوع دوم بر اساس فیزیولوژی چیست؟

   باز نگری های مختلف اثرات فعالیت جسمی را روی مقاومت انسولین و قند مشخص کرده است . دلایل فیزیولوژی را رقابت بین فعالیت جسمی و دیابت نوع دوم را ممکن می سازد. به طور کلی افراد فعال انسولین و قند خون را بهتر از افراد غیر فعال جذب می کند. تحقیق بر روی ورزش نشان داد که فعالیت جسمی باعث پیشرفت عملکرد انسولین شد.  به عبارت دیگر مقاومت انسولین را کاهش می دهد . تحقیقات ورزشی همچنین با عث پیشرفت متابولیسم قند در افراد معمولی و بیماران دیابتی نوع دوم است. بر اساس این تحقیقات فعالیت جسمی پدیدار می شود که عملکرد انسولین را در افراد در معرض خطر بیماری دیابت تحت فشار قرار می دهد. یعنی افرادی مه ظرفیت مخفی کردن انسولین را داردند ، سالم هستند و مقاومت انسولین را که دلیل اصلی تحمل قند غیر عادی است .

   مرض چاقی و پخش چربی عامل های اصلی برای مقاومت انسولین هستند. بنابراین جدا در بیماری نوع دوم دخالت دارد. فعالیت جسمی نیز در مورد افراد چاق این مطلب را نشان داده است. با تحقیقات انجام شده می توان بوسیله ورزش هر دو پارامتر را کاهش داد. به عبارت دیگر این موضوع امکان پذیر است که با فعالیت جسمی نیز احتمال دارد که از بیماری دیابت نوع دوم جلوگیری یا آن را به تاخیر اندازیم. و چربی و چربی غیر عادی را کاهش دهیم. به طور خلاصه اینکه فعالیت جسمی احتمالا نه فقط به طور مستقیم مربوط به دیابت نوع دوم بلکه به طور غیر مستقیم روی چاقی اثر می گزارد.

   از آنجاییکه بیشتر افراد دیابتی نوع دوم چاق هستند و تغییر در فعالیت اغلب کم است اما تغییرات مهمی در چاقی و ترکیب بدن هست. تفکیک کاملی از اثرات فعالیت و ترکیب نوع دوم دیابت دارد که اغلب مشکل ست. به هر حال مطالعات کلینیکی اثرات ورزش را روی بیماران دیابتی نوع دوم انجام داده است و رابطه مستقیمی بین چاقی و بیماری هست.

  آیا تحقیقات روی بیماری های مسری ، رابطه بین فعالیت جسمی و دیابت نوع دوم را حمایت می کند؟

   در طول سالها ، بر اساس مشاهدات و تحقیقات روی بیماری های مسری ، از  رابطه بین فعالیت جسمی  ودیابت نوع دوم حمایت شده است. اخیرا جامعه از سبک زندگی سنتی فاصله گرفته اس که منجر به افزایش دیابت نوع دوم است. در این زمینه مدارکی را از افرادی که در محیط های مدرن تر دچار دیابت شده اند نسبت به افرادی که به صورت ارثی به این بیماری مبتلا شده اند . در این تحقیقات فرق بین فعالیت جسمی به عنوان توضیحات جزوی برای شیوع دیابت است . نتایج تحقیقات در مورد بیماریهای مسری در بخشهای زیر توضیح داده شده است . اطلاعات جمع آوری شده درباره نتیجه سلامتی و عامل خطر روی گروه یکسان بدست آمده است. این نوع بیماری مسری محدود است زیرا غیر ممکن است که بی دلیل به وجود اید. تحقیقات نشان داده است که بی تحرکی جسمی با دیابت نوع دوم و تحمل قند در ارتباط هستند. گروه بیماران دیابتی نوع دوم مورد تحقیق  اخیرا کمتر تحرک داشته اند. علاوه بر این مطالعات نشان داده است که رابطه بن فعالیت جسمی و قند در افراد بدون دیابت نوع دوم معمولا قند خون را بعد از تست نشان داده است . از افراد دیابتی و سالم سوالاتی را در مورد گذشته شان پرسیده اند.  اگرچه نوع تحقیق در مورد جایی که نتیجه بیماری رخ داده است ارزشمند است ممکن است افراد یاد آوری کنند زمانی را که بیماری رخ داده است یک مثال در رابطه با این نوع تحقیق توسط    بیمار هندی اثبات شده است که افرادی که فعالیت جسمی در طول زندگی نداشته اند در معرض این بیماری قرار گرفته اند.


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