The relationship between glycaemic status and the risk of third, fourth and sixth cranial nerve palsy: a nationwide population-based study (2009-2018).

purposeThe purpose of this study was to evaluate the association between glycaemic status and the incidence of third, fourth, and sixth cranial nerve palsy (CNP).

methodsThis is a retrospective nationwide population-based cohort study using South Korean National Health Insurance Service (NHIS) data since 2009. Health check-up data of 4,067,842 individuals aged from 20 to 90 years in the period from 1 January 2009 to 31 December 2018 were analysed. The subjects were classified according to glycaemic status as follows: non-diabetes, impaired fasting glucose (IFG), newly detected diabetes, diabetes duration <5 years, and diabetes duration ≥5 years. The primary endpoint of this study was the incidence of third, fourth or sixth CNP. Hazard ratio (HR) and 95% confidence interval (CI) of CNP were estimated using Cox proportional hazards regression analysis. In Model 5, we adjusted for age, gender, smoking status, alcohol consumption, physical activity, body mass index, hypertension, dyslipidaemia, and chronic kidney disease.

resultsDuring the follow-up period (mean, 6.3 years), 5835 cases of third, fourth, or sixth CNP were identified with 4,062,007 control cases. In the adjusted model 5, the adjusted HR for third, fourth, and sixth CNP in the IFG group was 1.098 (95% CI 1.030 - 1.171); in the newly detected diabetes group, 1.779 (95% CI 1.587-1.994); in the diabetes duration <5 years group, 1.921 (95% CI 1.731-2.131); and in the diabetes duration ≥5 years group, 2.571 (95% CI 2.343-2.820). Using the Kaplan-Meier curve, the log-rank test demonstrated an increase in the incidence of CNP proportional to the duration of diabetes (p < 0.001).

conclusionsThis large-scale, population-based cohort study suggests that the risk of third, fourth, and sixth CNP significantly increased in patients with IFG and diabetes compared to those with normal glycaemic status.