Hypertension, hypercholesterolemia, diabetes, and risk of Parkinson disease

Abstract

Objective: To determine whether history of hypertension, hypercholesterolemia, or diabetes is associated with risk of Parkinson disease (PD).

Methods: Prospective study among participants in two large cohorts: the Nurses' Health Study (121,046 women) and the Health Professionals Follow-up Study (50,833 men). Mean duration of follow-up was 22.9 years in women, aged 30 to 55 years at baseline, and 12.6 years in men, aged 40 to 75 years at baseline. Relative risks (RRs) of PD were estimated from a Cox proportional hazards model adjusting for potential confounders.

Results: We identified a total of 530 incident cases of PD during the follow-up. Risk of PD was not associated with self-reported history of hypertension (RR = 0.96, 95% CI = 0.80 to 1.15), high cholesterol (RR = 0.98, 95% CI = 0.82 to 1.19), or diabetes (RR = 1.04, 95% CI = 0.74 to 1.46), after adjusting for age and smoking in pack-years. Risk of PD decreased modestly with increasing levels of self-reported total cholesterol (RR for a 50-mg/dL increase in total cholesterol = 0.86, 95% CI = 0.78 to 0.95, p for trend = 0.02), but use of cholesterol-lowering drugs was not associated with PD risk (RR comparing users with nonusers = 0.85, 95% CI = 0.59 to 1.23). Among individuals with PD, systolic blood pressure was similar to noncases up to the time of diagnosis but declined afterward.

Conclusions: Results of this large prospective study suggest that Parkinson disease risk is not significantly related to history of hypertension, hypercholesterolemia, or diabetes but may modestly decline with increasing blood cholesterol levels.

Figure

Means and 95% CIs of differences between observed and expected blood pressure (DBP and SBP) of PD cases adjusting for age, age squared, and BMI, plotted in relation to time of diagnosis Sample sizes in order of time points for systolic blood pressure (SBP) are 82, 140, 176, 216, 140, 108, 102, 91, 54, and 29, and those for diastolic blood pressure (DBP) are 81, 129, 142, 170, 109, 88, 83, 77, 51, and 29. The time points at 8 years after diagnosis for both DBP and SBP include only female participants—no men had adequate follow-up data at 8 years after diagnosis. p for trend for SBP after diagnosis = 0.02. Mean residual DBP among Parkinson disease (PD) cases at 1.3 and 5 years after diagnosis was significantly lower than that among individuals without PD (p = 0.005 and 0.01, respectively); however, the trend in DBP after diagnosis was not significant. BMI = body mass index.