A Prospective Study of Cardiorespiratory Fitness and Risk of Type 2 Diabetes in Women

Abstract

OBJECTIVE -The purpose of this study was to determine the independent and joint associations of cardiorespiratory fitness (CRF) and BMI with the incidence of type 2 diabetes in women.RESEARCH DESIGN AND METHODS -An observational cohort of 6,249 women aged 20 -79 years was free of baseline cardiovascular disease, cancer, and diabetes. CRF was measured using a maximal treadmill exercise test. BMI was computed from measured height and weight. The incidence of type 2 diabetes was identified primarily by 1997 American Diabetes Association criteria.RESULTS -During a 17-year follow-up, 143 cases of type 2 diabetes occurred. Compared with the least fit third, the multivariate (including BMI)-adjusted hazard ratio (HR) (95% CI) was 0.86 (0.59 -1.25) for the middle third and 0.61 (0.38 -0.96) for the upper third of CRF. For BMI, the multivariate (including CRF)-adjusted HR (95% CI) was 2.34 (1.55-3.54) for overweight individuals and 3.70 (2.12-6.44) for obese individuals, compared with normal-weight patients. In the combined analyses, overweight/obese unfit (the lowest one-third of CRF) women had significantly higher risks compared with normal-weight fit (the upper two-thirds of CRF) women.CONCLUSIONS -Low CRF and higher BMI were independently associated with incident type 2 diabetes. The protective effect of CRF was observed in individuals who were overweight or obese, but CRF did not eliminate the increased risk in these groups. These findings underscore the critical importance of promoting regular physical activity and maintaining normal weight for diabetes prevention. Diabetes Care 31:550-555, 2008

Associations of Cardiorespiratory Fitness and Obesity With Risks of Impaired Fasting Glucose and Type 2 Diabetes in Men

“…Some previous studies concluded that the relative contribution of obesity was more important than physical activity on the risk of type 2 diabetes in women (6,7). However, in our recent study of women using objectively measured fitness instead of self-reported physical activity, obesity and fitness made similar contributions to the risk of type 2 diabetes (15). To date, no study on this issue has been conducted in men.…”

“…We created six categories of BMI and fitness combinations and four categories of waist girth or percent body fat and fitness combinations using nonobese and fit men as the referent. In Cox regression models, baseline age, examination year, parental diabetes, current smoking, alcohol consumption, blood pressure, total cholesterol, baseline IFG, BMI, and treadmill time were considered as potential confounders as in previous studies (11)(12)(13)15,23). The proportional hazards assumption was tested by examining the log-log survival plots grouped on exposure categories.…”

Cardiorespiratory Fitness and Incidence of Type 2 Diabetes in United States Veterans on Statin Therapy

“…[16][17][18] We have also shown that both statin therapy and increased cardiorespiratory fitness were independently associated with lower mortality risk in those treated and not treated with statins. 19 Additionally, the combination of statin therapy and increased cardiorespiratory fitness was more effective in lowering mortality risk than either alone.…”

Investigation of Plasma Visfatin Changes in Women with Type 2 Diabetes followed by Endurance, Resistance and Combined Exercise: The Role of Lipid Profile, Glycemic Indices and Insulin Resistance

“…Epidemiological studies confirm that physical activity like regular exercise is related to the decreased incidence of DMT2 [9][10][11][12]. Also several studies have demonstrated that exercise alone has clinical benefits, such as improving insulin sensitivity, reducing glycated hemoglobin (A1c) and increasing peak oxygen consumption (VO 2 peak) [13][14][15].…”