Abstract:
Background: Distal sensory neuropathy is a common disorder in the peripheral nervous system. We aimed to investigate the association between reproductive history factors and distal sensory neuropathy among the US postmenopausal women aged 40 years and over. We also explored the heterogeneity of these associations by age.
Methods: A cross sectional study was conducted with data from postmenopausal women aged 40 years and over in National Health and Nutrition Examination Survey 1999-2004. Women with diabetes, stroke, cancer, cardiovascular diseases, thyroid disease, liver disease, weak/failing kidneys, or amputation were excluded. Distal sensory neuropathy was measured via 10-gram monofilament test and all reproductive variables and exogenous hormone use were collected by interview questionnaire. A multivariable design-based binary logistic regression was used to analyze the association between the reproductive history variables and distal sensory neuropathy accounting for sample stratification, clustering, and weighting. Heterogeneity was assessed using interaction terms overall and via subgroup analysis.
Results: A total of 1144 postmenopausal women were included in this study. Women with distal sensory neuropathy tend to report age at menarche ≤ 11 years (OR = 8.13, 95%CI: 1.24 - 53.28), time since menopause > 20 years (OR = 3.18, 95%CI: 1.32 - 7.68) while those without distal sensory neuropathy tend to report history of breastfeeding (OR = 0.45, 95%CI: 0.21 - 0.99) and exogenous hormone use (OR = 0.41, 95%CI: 0.19 - 0.87). We observed that a significant interaction term of menarche with race (p for interaction = 0.027). Race was also a significant effect modifier for these associations based on subgroup analysis; however, subgroup analysis by age could not be conducted because of large amounts of missing data in older age group (>70 years).
Conclusions: Age at menarche, time since menopause, breastfeeding and exogenous hormone use are associated with distal sensory neuropathy. There is race-based heterogeneity in these associations among US postmenopausal women aged 40 years and over. Our findings may provide a rationale for the etiology of distal sensory neuropathy among US postmenopausal women. Further research should investigate the underlying mechanism.
