A prospective study of exercise and incidence of diabetes among US male physicians

Department of Nutrition , Harvard University, Cambridge, Massachusetts, United States
JAMA The Journal of the American Medical Association (Impact Factor: 35.29). 08/1992; 268(1):63-7. DOI: 10.1001/jama.268.1.63
Source: PubMed


To examine prospectively the association between regular exercise and the subsequent development of non-insulin-dependent diabetes mellitus (NIDDM).
Prospective cohort study including 5 years of follow-up.
21,271 US male physicians participating in the Physicians' Health Study, aged 40 to 84 years and free of diagnosed diabetes mellitus, myocardial infarction, cerebrovascular disease, and cancer at baseline. Morbidity follow-up was 99.7% complete.
Incidence of NIDDM.
At baseline, information was obtained about frequency of vigorous exercise and other risk indicators. During 105,141 person-years of follow-up, 285 new cases of NIDDM were reported. The age-adjusted incidence of NIDDM ranged from 369 cases per 100,000 person-years in men who engaged in vigorous exercise less than once weekly to 214 cases per 100,000 person-years in those exercising at least five times per week (P, trend, less than .001). Men who exercised at least once per week had an age-adjusted relative risk (RR) of NIDDM of 0.64 (95% Cl, 0.51 to 0.82; P = .0003) compared with those who exercised less frequently. The age-adjusted RR of NIDDM decreased with increasing frequency of exercise: 0.77 for once weekly, 0.62 for two to four times per week, and 0.58 for five or more times per week (P, trend, .0002). A significant reduction in risk of NIDDM persisted after adjustment for both age and body-mass index: RR, 0.71 (95% Cl, 0.56 to 0.91; P = .006) for at least once per week compared with less than once weekly, and P, trend, .009, for increasing frequency of exercise. Further control for smoking, hypertension, and other coronary risk factors did not materially alter these associations. The inverse relation of exercise to risk of NIDDM was particularly pronounced among overweight men.
Exercise appears to reduce the development of NIDDM even after adjusting for body-mass index. Increased physical activity may be a promising approach to the primary prevention of NIDDM.

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    • "The elderly prefer to exercise at a low to moderate intensity. However, a large amount of exercise performed at a low level of intensity was found to have no relationship with physical fitness (Manson et al., 1992). On the other hand, a study (Morikawa et al., 2011) conducted with 666 participants more than 65 yr old found that walking at a high level of intensity four times in four months significantly improved their BMI, body fat %, blood pressure, glucose, muscle strength, and maximal oxygen uptake. "
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    08/2014; 10(4):225-9. DOI:10.12965/jer.140136
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    • "Bed rest (BR) has previously been used as a model to study the effects of sedentarism. Prior BR studies demonstrated that prolonged inactivity leads to reductions in conduit artery diameter [7], decreased reactive hyperemia (RH) [8], development of insulin resistance [9], type 2 diabetes [10], upregulation of the renin-angiotensin axis [11], and possibly vascular dysfunction [12]. Brachial artery flowemediated dilatation (FMD) and arterial stiffness measured by arterial tonometry are used to assess vascular function, and when they are impaired, they have been independently associated with increased cardiovascular risk [13e16]. "
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    • "For example, a study by Helmrich et al. [6] followed 5,990 male graduates of the University of Pennsylvania over 14 years and found that the risk of developing diabetes is reduced by 6% for every 500 kcal increase in weekly exercise. Furthermore, a study that followed 21,271 male U.S. doctors over five years revealed that even a once-weekly bout of exercise at an intensity that is sufficient to cause sweating reduced the risk of developing diabetes [7]. In addition, results from a study that followed 87,253 female U.S. nurses over eight years showed that the group that exercised at least once a week at an intensity sufficient to cause sweating had a relative risk of developing diabetes of 0.84 compared with a group that exercised less than once a week [8]. "
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