Japanese women who engaged in aerobic exercise with weight resistance training developed type 2 diabetes less often than those who exercised less frequently, according to findings from a retrospective cohort study published in the Journal of Diabetes Investigation.
“The onset of type 2 diabetes is not only related to genetic factors, but also to environmental factors, especially lifestyle, and proper diet and physical activity are critical to delay and/or prevent its onset,” Susumu S. Sawada, PhD, professor in the school of sport sciences at Waseda University in Japan, and colleagues wrote. “Hence, it is important, in the consideration of effective measures, to identify the necessary components of diet and physical activity for the prevention of type 2 diabetes.”
Sawada and colleagues examined data from the Curves Japan Study on 10,680 women (mean age, 57.8 years; mean BMI, 23.2 kg/m2) who were enrolled as members in Curves fitness training facilities in Japan from July 2005 to July 2010. The women took part in 30-minute combined aerobic and resistance training programs, which consisted of 24 minutes of combined exercise and 6 minutes of stretching. After a median follow-up period of 5 years, participants completed questionnaires about their medical history currently and at enrollment and to report whether and when they were diagnosed with diabetes.
At follow-up, 166 participants had received a type 2 diabetes diagnosis.
The researchers divided the study population into four quartiles based on frequency of training at their fitness center. With the least frequent group (1-41 sessions in 5 months) used as reference, the researchers found a negative linear relationship between training frequency and type 2 diabetes development. Women in the highest training quartile (67-125 sessions in 5 months) had the lowest diabetes risk (HR = 0.69; 95% CI, 0.44-1.07), but the risk was also lower for women in the second-highest (55-66 sessions in 5 months; HR = 0.73; 95% CI, 0.48-1.13) and third-highest (42-54 sessions in 5 months; HR = 0.95; 95% CI, 0.64-1.41) frequency groups compared with the lowest quartile. These results held after multivariable-adjustments for the highest (HR = 0.61; 95% CI, 0.39-0.95), second-highest (HR = 0.69; 95% CI, 0.45-1.06) and third-highest (HR = 0.84; 95% CI, 0.56-1.26) quartiles. The researchers also found that lower BMI had a stronger connection with this negatively linear association compared with higher BMI (P = .003). Similar results were found when comparing lower thigh circumference with greater thigh circumference (P = .013).
“It is likely that combined aerobic and resistance training simultaneously provides the individual effects unique to aerobic exercise and resistance training, respectively. Insulin-mediated blood glucose uptake occurs mainly in skeletal muscles. Resistance training facilitates glycemic control by increasing muscle mass, which incorporates blood glucose and thus might delay and/or prevent development of type 2 diabetes,” the researchers wrote. “Aerobic exercise might delay and/or prevent the development of type 2 diabetes by improving insulin resistance through modification of muscle quality, including reduction of adiposity and increase of glucose transporter type 4 in muscle cells.” – by Phil Neuffer
Disclosures: Sawada reports he received research funding from Curves Japan. Please see the study for all other authors’ relevant financial disclosures.