Physical Fitness and Cardiovascular Risk Factors in Novel Diabetes Subgroups.

CONTEXT: Physical inactivity promotes insulin resistance and increases the risk of diabetes and cardiovascular disease. Recently introduced clustering based on simple clinical measures identified diabetes subgroups (clusters) with different risks of diabetes-related comorbidities and complications. OBJECTIVE: This study aims to determine differences in physical fitness and cardiovascular risk between diabetes subgroups and a glucose-tolerant control group (CON). We hypothesized that the severe insulin-resistant diabetes (SIRD) subgroup would be associated with lower physical fitness and increased cardiovascular risk. METHODS: The physical fitness and cardiovascular risk of 746 participants with recent-onset diabetes (diabetes duration of < 12 months, aged 18-69 years) and 74 CONs of the German Diabetes Study (GDS), a prospective longitudinal cohort study, were analyzed. Main outcome measures included physical fitness (VO2max from spiroerogometry), endothelial function (flow- and nitroglycerin-mediated dilation), and cardiovascular risk scores (Framingham Risk Scores for Coronary Heart Disease [FRS-CHD] and Atherosclerotic CardioVascular Disease [ASCVD] risk score). RESULTS: VO2max was lower in SIRD than in CON, severe autoimmune diabetes (SAID) (both P < .001), and mild age-related diabetes (MARD) (P < .01) subgroups, but not different compared to severe insulin-deficient diabetes (SIDD) (P = .98) and moderate obesity-related diabetes (MOD) subgroups (P = .07) after adjustment for age, sex, and body mass index. Endothelial function was similar among all groups, whereas SAID had lower FRS-CHD and ASCVD than SIRD, MOD, and MARD (all P < .001). CONCLUSION: Despite comparable endothelial function across all groups, SIRD showed the lowest physical fitness. Of note, SAID had the lowest cardiovascular risk within the first year after diabetes diagnosis compared to the other diabetes subgroups.

Reduced Muscle Strength Is Associated With Insulin Resistance in Type 2 Diabetes Patients With Osteoarthritis.

CONTEXT: Type 2 diabetes is associated with a greater risk for musculoskeletal disorders, yet its impact on joint function remains unclear. OBJECTIVE: We hypothesized that patients with type 2 diabetes and osteoarthritis would exhibit musculoskeletal impairment, which would associate with insulin resistance and distinct microRNA profiles. METHODS: Participants of the German Diabetes Study with type 2 diabetes (T2D, n = 39) or normal glucose tolerance (CON, n = 27), both with (+OA) or without osteoarthritis (-OA) underwent intravenous glucose tolerance and hyperinsulinemic-euglycemic clamp tests. Musculoskeletal function was assessed by isometric knee extension strength (KES), grip strength, range of motion (ROM), and balance skills, while neural function was measured by nerve conductance velocity (NCV). Arthritis-related symptoms were quantified using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire, serum arthritis-related microRNA using quantitative polymerase chain reaction. RESULTS: Insulin sensitivity was lower in T2D+OA vs T2D-OA (4.4 ±â€…2.0 vs 5.7 ±â€…3.0 mg* kg-1*min-1) and in CON+OA vs CON-OA (8.1 ±â€…2.0 vs 12.0 ±â€…2.6 mg*kg-1,*min-1, both P < .05). In T2D+OA, KES and ROM were 60% and 22% lower than in CON+OA, respectively (both P < .05). Insulin sensitivity correlated positively with KES (r = 0.41, P < .05) among T2D, and negatively with symptom severity in CON and T2D (r = -0.60 and r = -0.46, respectively, P < .05). CON+OA and T2D+OA had inferior balance skills than CON-OA, whereas NCV was comparable in T2D+OA and T2D-OA. Expression of arthritis-related microRNAs was upregulated in T2D compared to CON, but downregulated in CON+OA compared to CON-OA (P < .05), and did not differ between T2D+OA and T2D-OA. CONCLUSION: Musculoskeletal impairment and osteoarthritis-related symptoms are associated with insulin resistance. Type 2 diabetes can mask changes in arthritis-related microRNA profiles.