Diabetes is a heterogenous disorder, and recently new, homogenous subgroupings have been proposed (1). These are: mild age-related diabetes (MARD), mild obesity-related diabetes (MOD), severe insulin-resistant diabetes (SIRD), severe insulin-deficient diabetes (SIDD), and severe autoimmune diabetes (SAID). This study investigated differences in muscle health between subgroups and normoglycaemia.
Male participants (n=895, 20-97yr) were drawn from the Geelong Osteoporosis Study. Diabetes (n=105) was defined as fasting plasma glucose≥7.0mmol/L, self-report and/or use of antihyperglycaemic medication. Using hierarchical clustering, men with diabetes were categorised into the SAID subgroup (positive glutamic acid decarboxylase antibodies, n=3), and using K-means clustering, those remaining were categorised into the other subgroups. Lean mass was measured using DXA (Lunar DPX-L and GE-Prodigy). Gait speed was assessed using the timed-up-and-go test. A manual muscle tester (Nicolas, Model 01160) was used to assess maximum quadricep, hip abductor, and hip flexor strength using a ‘break-test’ technique. The SAID subgroup was excluded from analyses due to low numbers (n=3).
The MARD subgroup had the lowest muscle mass and gait speed compared to normoglycaemia. After adjusting for age and weight, leg (9.1kg, 95%CI 7.9-10.3 vs 9.8kg, 95%CI 8.9-10.8, p=0.032) and appendicular lean mass/height2 (5.1kg/h2, 95%CI 4.6-5.6 vs 5.5, 95%CI 5.1-5.9, p=0.012) and gait speed (5.65s, 95%CI 4.7-6.6 vs 3.93s, 95%CI 3.49-4.38, p<0.001) were significantly lower. In the MOD and SIRD subgroups lean mass was similar to normoglycaemia before adjustment, however, after adjustment, leg lean mass was lower, 9.0kg (95%CI 7.7-10.3, p=0.030) and 9.2kg (95%CI 7.7-10.6, p=0.010) respectively.
The subgroups with older age, higher BMI and insulin resistance but not insulin deficiency had lower relative lean mass and poorer muscle health than normoglycaemia. Further study is required to better understand the determinants of muscle mass and strength in diabetes.