Muscle Strength in Type 2 Diabetes

Muscle Strength in Type 2 Diabetes Henning Andersen 1 , Søren Nielsen 2 , Carl E. Mogensen 2 and Johannes Jakobsen 1 1 Department of Neurology, Aarhus University Hospital, Aarhus, Denmark 2 Medical Department M (Endocrinology and Diabetes), Aarhus University Hospital, Aarhus, Denmark Address correspondence and reprint requests to Henning Andersen, MD, Department of Neurology, Aarhus University Hospital, Nørrebrogade 44, 8000 Aarhus C, Denmark. E-mail: hande{at}akh.aaa.dk Abstract Motor function in type 2 diabetes is largely unknown. In 36 type 2 diabetic patients and in 36 control subjects matched for sex, age, weight, height, and physical activity, strength of flexors and extensors at elbow, wrist, knee, and ankle was assessed at isokinetic dynamometry. The degree of neuropathy was determined by clinical scores, nerve conduction studies, and quantitative sensory testing. Eventually, all results were summed to obtain a neuropathy rank-sum score (NRSS). The degree of nephropathy and retinal condition were also evaluated. Diabetic patients had a 17 and 14% reduction of strength of ankle flexors ( P < 0.02) and ankle extensors ( P < 0.03), respectively. At the knee, strength of extensors and flexors was reduced by 7% (NS) and 14% ( P < 0.05), respectively. At the elbow and wrist, muscle strength was preserved. The NRSS was related to the strength at the ankle ( r = −0.45, P < 0.01) and knee ( r = −0.42, P < 0.02). Following multiple regression analysis, the NRSS but not the degree of nephropathy or retinopathy was related to strength at the ankle and knee. In conclusion, type 2 diabetic patients may have muscle weakness at the ankle and knee related to presence and severity of peripheral neuropathy. CMAP, compound muscle action potential MNCV, motor nerve conduction velocity NDS, neurological disability score NRSS, neuropathy rank-sum score NSS, neuropathy symptom score SNAP, sensory nerve action potential SNCV, sensory nerve conduction velocity VPT, vibration perception threshold Footnotes Accepted March 15, 2004. Received January 7, 2004. DIABETES