Clinical research study
Physical Activity, Body Mass Index, and Diabetes Risk in Men: A Prospective Study

https://doi.org/10.1016/j.amjmed.2009.02.008Get rights and content

Abstract

Objective

Physical activity has been associated with lower diabetes risk, but several prospective studies among women found that activity only slightly attenuated the diabetes risk associated with high body mass index (BMI). We investigated the independent and joint associations between vigorous activity and BMI on diabetes risk in men.

Methods

This was a prospective cohort design within the Physicians' Health Study, using Cox proportional hazards models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) of incident diabetes in 20,757 men without diabetes at baseline. Models were based on self-reported BMI and exercise frequency at baseline, first separately and then with a 6-category joint variable combining World Health Organization BMI category (normal/overweight/obese) with activity status (active/inactive) using weekly vigorous activity as the threshold.

Results

After a median follow-up of 23.1 years, there were 1836 cases of incident diabetes. Compared with active participants with normal BMIs, active but overweight and obese men had multivariable-adjusted HRs of 2.39 (95% CI, 2.11-2.71) and 6.22 (95% CI, 5.12-7.56). Inactive men with normal, overweight, or obese BMIs had multivariable-adjusted HRs of 1.41 (95% CI, 1.19-1.67), 3.14 (95% CI, 2.73-3.62), and 6.57 (95% CI, 5.25-8.21).

Conclusion

Active men with normal and overweight BMIs had lower diabetes hazards than their inactive counterparts, but no difference by weekly activity was seen in obese men. Elevated BMI is a key driver of diabetes risk, with relatively modest attenuation by activity.

Section snippets

Study Population

The Physicians' Health Study was a randomized, controlled trial of aspirin and beta-carotene in the primary prevention of cardiovascular disease and cancer. Details on the Physicians' Health Study design and recruitment have been reported.13 The original cohort of 22,071 US male physicians aged 40 to 84 years at enrollment has been followed continuously since 1982 via annual questionnaires, with approval from the Institutional Review Board at the Brigham and Women's Hospital (Boston, MA). The

Results

After a median follow-up of 23.1 years (431,126 person-years) among initially nondiabetic men with an average baseline age of 53 years, there were 1836 new cases of diabetes occuring in 8.9% of the population, with incidence rates for men in the normal, overweight, and obese groups of 2.4, 6.1, and 15.0 cases per 1000 person-years, respectively. Men who reported vigorous activity at least weekly had a diabetes incidence rate of 3.7 per 1000 person-years, compared with 5.8 per 1000 in those who

Conclusions

In this prospective cohort study of 20,757 men, weekly vigorous activity reduced the hazards of type 2 diabetes for those who were normal weight or overweight when studied as a combined exposure. Although regular activity showed the strongest overall association in obese men when studied as an isolated exposure, the joint analysis of regular activity and BMI together revealed that in the setting of elevated BMI, vigorous physical activity does not attenuate the harm of excess body weight to a

Acknowledgments

We are indebted to the thousands of participants of the Physicians' Health Study for their outstanding commitment and to the entire Physicians' Health Study staff for their expertise and assistance.

References (29)

  • A.R. Weinstein et al.

    Joint effects of physical activity and body weight on diabetes and cardiovascular disease

    Exerc Sport Sci Rev

    (2006)
  • J.E. Manson et al.

    Walking compared with vigorous exercise for the prevention of cardiovascular events in women

    N Engl J Med

    (2002)
  • A.R. Weinstein et al.

    Relationship of physical activity vs body mass index with type 2 diabetes in women

    JAMA

    (2004)
  • A.R. Weinstein et al.

    The joint effects of physical activity and body mass index on coronary heart disease risk in women

    Arch Intern Med

    (2008)
  • Cited by (28)

    • Effect of parental history of diabetes on markers of inflammation, insulin resistance and atherosclerosis in first degree relatives of patients with type 2 diabetes mellitus

      2018, Diabetes and Metabolic Syndrome: Clinical Research and Reviews
      Citation Excerpt :

      All subjects were asked about frequency of doing exercise vigorously enough to work up a sweat. We considered participants reporting vigorous exercise at least once weekly to be active [13]. Only normoglycemic healthy adults were included in the study.

    • ‘Mendelian randomization’: an approach for exploring causal relations in epidemiology

      2017, Public Health
      Citation Excerpt :

      GWASs have helped in identifying genetic correlates of modifiable traits like smoking23 and cardiometabolic traits like lipid levels, glycemic and anthropometric traits.24–26 These traits sometimes also act as confounders while evaluating the associations between the exposures and disease outcomes e.g. body mass index (BMI) may act as a confounder for studying the association of physical activity and diabetes.27 The detection of new genetic variants by GWAS has improved to some extent the risk prediction of diseases and their related traits.28,29

    • Determinants of new-onset diabetes in older adults-Results of a national cohort study

      2015, Clinical Nutrition
      Citation Excerpt :

      In a prospective study examining the relative contributions and joint association of physical activity with NOD in a cohort of 37,878 women, Weinstein et al. [3] found that although physical inactivity and excessive body weight are independent predictors of incident diabetes, and physical activity has a modulating effect on the impact of excessive body weight on NOD, in combined analyses, the magnitude of the association of NOD with BMI was greater than with physical activity [3]. In fact, BMI was found to be the key driver of diabetes risk, while physical activity can modestly attenuate the risk [19]. On the other hand, longer sitting time which may often mean less physical activity, has been observed to be positively associated with higher risk of type-2 diabetes [20].

    • Effects of auricular stimulation in the cavum conchae on glucometabolism in patients with type 2 diabetes mellitus

      2014, Complementary Therapies in Medicine
      Citation Excerpt :

      We could not find a statistically significant reduction on post-treatment mean value of FBG and P2BG. It may be related to the fact that blood glucose can fluctuate by daily dietary intake of carbohydrate or physical activities.18–21 Larger sample size may be needed to detect whether the auricular acupuncture can reduce FBG and P2BG.

    • Obesity and risk factors for cardiovascular disease and type 2 diabetes: Investigating the role of physical activity and sedentary behaviour in mid-life in the 1958 British cohort

      2014, Atherosclerosis
      Citation Excerpt :

      For type 2 diabetes, a review of 8 studies found that obese groups who were physically inactive had an increased risk greater than the additional effect of each factor (obesity and inactivity) separately [19], whilst an earlier study had reported stronger protective effects of activity among obese individuals [9]. Yet, not all studies show greater benefits of activity amongst obese groups for type 2 diabetes [20] or coronary heart disease [2,5]. Research is scarce on whether benefits of activity vary for obese and non-obese groups across multiple CVD and diabetes biomarkers and whether there are corresponding patterns for sedentary behaviour.

    View all citing articles on Scopus

    Funding: The Physicians' Health Study is supported by grants CA-34944 and CA-40360 and CA-097193 from the National Cancer Institute and grants HL-26490 and HL-34595 from the National Heart, Lung, and Blood Institute, Bethesda, Maryland. Dr Siegel received support from the Office of Research and Development, Cooperative Studies Program, Department of Veterans Affairs.

    Conflict of Interest: None.

    Authorship: All authors had access to the data and played a role in writing this manuscript.

    View full text