Hyperhomocysteinaemia is not related to risk of distal somatic polyneuropathy: The Hoorn Study

Objective. Distal somatic polyneuropathy is a major contributing factor in the pathogenesis of chronic foot infections and ulcers, and may lead to lower limb amputations. Both metabolic and vascular abnormalities may contribute to the development of impaired nerve function. We therefore assessed the association between hyperhomocysteinaemia, a risk factor for cardiovascular disease, and polyneuropathy. Design, setting and subjects. We studied an age-, sex- and glucose-tolerance-stratified random sample of a 50- to 75-year-old general Caucasian population in the Hoorn Study (N = 629). Any polyneuropathy (N = 95) was defined as the absence of at least two of the three following sensory modalities or reflexes of either foot: light touch sense, ankle reflex and vibration sensation. Definite polyneuropathy (N = 25) was present if, in addition, the vibration perception threshold of the right big toe was abnormal. Results. The prevalence of any polyneuropathy was 12.4% (33 of 266) in subjects with normal glucose tolerance (NGT), 12.6% (21 of 167) in those with impaired glucose tolerance (IGT), and 25.3% (41 of 162) in those with type 2 diabetes. The prevalence of definite polyneuropathy was 2.6% (7 of 266) in subjects with NGT, 2.4% (4 of 167) in those with IGT and 8.7% (14 of 161) in type 2 diabetic subjects. Polyneuropathy was associated with known risk factors such as diabetes, hyperglycaemia and body height. After adjustment for age, sex, HbA(1c) and hypertension, the odds ratio (95% CI) for any polyneuropathy per 5 μmol L^-1 (about 1 SD) serum total homocysteine increment was 1.00 (0.72-1.39). After adjustment for age and sex, it was 0.62 (0.21-1.89) for definite polyneuropathy. Conclusion. Although a weak relation (as judged from the confidence intervals) cannot be excluded, we conclude that hyperhomocysteinaemia is probably not related to risk of distal somatic polyneuropathy.