Diabetes Care, Vol 20, Issue 3 322-329, Copyright © 1997 by American Diabetes Association
Incidence of distal symmetric (sensory) neuropathy in NIDDM. The San Luis Valley Diabetes Study
ML Sands, SM Shetterly, GM Franklin and RF Hamman
Department of Preventive Medicine and Biometrics, University of Colorado School of Medicine, Denver 80262, USA.
OBJECTIVE: To determine the incidence and risk factors for distal symmetric
sensory neuropathy (DSN) in people with NIDDM. RESEARCH DESIGN AND METHODS:
Prospective follow-up was conducted from 1988 to 1992 on 231 people free of
DSN during the baseline period 1984-1988 (mean follow-up, 4.7 years).
Subjects with incident DSN (n = 66) were defined by any two of three
criteria: 1) bilateral paresthesia in legs or feet; 2) bilateral decreased
or absent ankle reflexes; and/or 3) bilateral decreased or absent cold
temperature discrimination in feet. Of all 66 cases, 42 had one positive
follow-up visit; 14 cases had 2 positive follow-up visits. RESULTS: The
overall incidence rate of DSN was 6.1 per 100 person-years (95% CI,
4.7-7.8). The rate for Hispanics (n = 164) and non-Hispanic whites (n =
67), adjusted for age, sex, and NIDDM duration, was 5.3 per 100
person-years (95% CI, 3.9-7.0) and 5.0 per 100 person-years (95% CI,
2.8-8.1), respectively. Adjusting for age and sex, higher glycohemoglobin
level and lower C-peptide secretion were associated with increased DSN but
were no longer predictive after accounting for duration of diabetes.
Logistic regression models found significantly increased risk of DSN for
insulin treatment, current smoking, and history of myocardial infarction.
Duration was related to DSN incidence until insulin treatment was included.
Other risk factors, including height, weight, family history of diabetes,
peripheral vascular disease, hypertension, urinary albumin,
protein:creatinine ratio, retinopathy, and alcohol use, were not
significantly related to incident DSN. CONCLUSIONS: Hispanic and
non-Hispanic whites with NIDDM have similar risks of DSN. Current cigarette
smoking and a history of myocardial infarction may represent independent
risk factors for DSN in addition to glycemic control.