Karvonen-Gutierrez CA, et al. - Researchers determined the influence of age-associated changes in muscle strength on diabetes risk. The mid-life was found to be a crucial risk period for diabetes onset. Diabetes among women may be prevented by improving muscle strength during mid-life.

Methods

• A total of 424 participants (60% Black, 40% White) from the Michigan site of the Study of Women’s Health Across the Nation contributed annual grip strength measures.
• These subjects were followed from 1996 to 2012 to detect incident cases of diabetes.
• The accepted definition for diabetes included self-reported physician-diagnosed diabetes, use of anti-diabetic medications or measured fasting glucose ≥126 mg/dl or haemoglobin A1c > 6.5%.

Results

• The observed 16-year diabetes incidence was 37%.
• Data showed average baseline weight-normalised grip strength (NGS, kg per kg body weight) to be 0.41 ± 0.12 and a mean of 0.29 ± 0.14 kg of absolute grip strength was lost per year.
• After adjusting for age, race/ethnicity, economic strain, smoking, menopause status, hormone use, physical activity and waist–hip ratio, each 0.1 higher NGS was found to be related to a 19% lower hazard of incident diabetes (P=0.006).
• Race/ethnic-stratified models revealed association of each 0.10 increase in NGS with a 54% lower hazard of incident diabetes (P < 0.0001) among White women, however, no statistically significant association was found among Black women.
• A statistically significant association was shown between baseline NGS and incident diabetes among Black women in models without adjustment for waist–hip ratio or restricted to women <48 years of age at baseline.
• No association was found between rate of change in grip strength and diabetes incidence.