Muscle Weakness

A Progressive Late Complication in Diabetic Distal Symmetric Polyneuropathy

  1. Christer S. Andreassen,
  2. Johannes Jakobsen and
  3. Henning Andersen
  1. Department of Neurology, Aarhus University Hospital, Aarhus, Denmark
  1. Address correspondence and reprint requests to Christer S. Andreassen, Department of Neurology, Aarhus University Hospital, 8000 Aarhus C, Aarhus, Denmark. E-mail: csa{at}akhphd.au.dk

Abstract

The aim of the study was to determine the progression of muscle weakness in long-term diabetes and its relation to the neuropathic condition. Thirty patients were recruited from a cohort of 92 diabetic patients who participated in a study on muscular function 6–8 years earlier. Nine subjects were nonneuropathic, 9 had asymptomatic neuropathy, and 12 had symptomatic neuropathy. Thirty matched control subjects who participated in the initial studies were also included. At follow-up, isokinetic dynamometry at the ankle, electrophysiological studies, vibratory perception thresholds, and clinical examination (neuropathy symptom score and neurological disability score [NDS]) were repeated. The annual decline of strength at the ankle was 0.7 ± 1.7% in control subjects, 0.9 ± 1.9% in nonneuropathic patients, 0.7 ± 3.1% in asymptomatic neuropathic patients, and 3.2 ± 2.3% in symptomatic neuropathic patients. In the symptomatic patients, the decline of muscle strength at the ankle was significant when compared with matched control subjects (P = 0.002) and with the other diabetic groups (P = 0.023). Also, the annual decline of muscle strength at the ankle was related to the combined score of all measures of neuropathy (r = −0.42, P = 0.03) and to the NDS (r = −0.52, P = 0.01). In patients with symptomatic diabetic neuropathy, weakness of ankle plantar and dorsal flexors is progressive and related to the severity of neuropathy.

Footnotes

    • Accepted December 14, 2005.
    • Received September 21, 2005.
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