Investigating the impact of body weight changes and blood lipids on risk for mild cognitive impairment in Parkinson's disease: a prospective cohort study.

BACKGROUND

Parkinson´s disease (PD) is a neurodegenerative disorder with high risk of cognitive impairment and dementia, where a known risk factor pattern includes low body weight and low blood lipids.

OBJECTIVES

This cohort study investigates prospective associations between changes in body mass index (BMI), plasma triglycerides (P-TG) and plasma cholesterol with mild cognitive impairment (MCI) at time of PD diagnosis.

METHODS

Patients with PD were identified prospectively in a community-based study of idiopathic Parkinsonism (n = 151) where the patient database was crosslinked to the Northern Sweden Health and Disease Study. The present prospective cohort study (n = 96) considers the timepoint for the healthcare visit the baseline and time for diagnosis as follow-up. At diagnosis of PD, 42 patients (43.8%) were diagnosed with MCI. Associations between prodromal body weight changes and blood lipids with risk of MCI at PD diagnosis were assessed with logistic regression [odd ratio (OR) and 95% confidence intervals (CIs)] adjusted for age and sex.

RESULTS

High P-TG at time of diagnosis were protective for MCI whereas a high age increased risk in patients with PD (OR: 0.31; 95% CI: 0.11, 0.87 and OR: 1.11; 95% CI: 1.02, 1.22, respectively). BMI was not predictive for MCI, neither at diagnosis nor for change over time (adjusted OR 0.99; 95% CI: 0.88, 1.13 and OR 1.12; 95% CI: 0.94, 1.33, respectively). An increase in P-TG was protective for MCI (OR: 0.34; 95% CI: 0.13, 0.88) whereas an interaction between change in BMI and P-TG (OR: 2.21; 95% CI: 1.02, 4.77) increased risk.

CONCLUSIONS

High risk of MCI in patients with PD at the time of diagnosis was associated with low levels of P-TG and an interaction between change in BMI and P-TG before diagnosis, suggesting that nutritional factors have complex influence on cognitive function in the prodromal stage of PD.