Influence of Body Mass Index (BMI) and Blood Pressure (BP) on Deep Brain Stimulation (DBS) Outcomes in Parkinson’s disease (PD) Patients
Julia See1, Scott Harcourt2, Annelly Bure-Reyes2, Dayana Rodriguez2, Corneliu Luca3, Jonathan Jagid3, Bonnie Levin3, Hannah Bullock1, Ihtsham Haq1, Marina Sarno2
1University of Miami Miller School of Medicine, 2University of Miami Department of Neurology, 3University of Miami
Objective:
PD literature supports a complex relationship between preoperative obesity, BP abnormalities, and post-DBS cognitive and motor outcomes. This study aims to improve on evidence associating BMI and BP with cognitive, emotional, and quality-of-life outcomes post-DBS.  
Background:
Previous studies indicate obesity and hypertension increase intra-/ post-operative complications. Up to 65% of PD patients may be overweight or obese, with obese patients having less axial motor improvement and worsened cognitive function six months post-DBS. PD patients have also demonstrated increased BP fluctuations compared to healthy controls. 
Design/Methods:
PD patients [n=28, Mage=62.6(8.8), 75% male, Medu=16.1(3.0), 92.9% STN) underwent pre-/post-DBS assessment (global cognition, language, memory, attention, processing speed, visuospatial ability) and emotional screenings via TeleNP. Systolic (M=130.0; SD=19.5) and diastolic (M=74.4; SD=16.0) BP (SBP, DBP), weight, and height were measured pre-DBS surgery. BMI was computed (M=27.3; SD=6.1). Logistic regression was used to predict neurocognitive performance using BMI, SBP, and DBP.  
Results:

BMI, SBP, and DBP predicted decline in verbal reasoning in post-, compared to pre-, DBS testing, but not other assessed domains. Model coefficient estimates of 0.40 [p=.02, OR=1.5 (95% CI [1.07, 2.10])] for BMI, 0.13 [p=.04, OR=1.13 (95% CI [1.01, 1.28])] for SBP, and -0.15 [p=.08, OR=0.86 (95% CI [0.73, 1.02])] for DBP were indicated. Model fit was robust [X2(3)=14.2, p=.003]. While holding BP constant: each unit increase in BMI predicted a 50% increase in odds of verbal reasoning decline (one-half SD or more), and a unit increase in SBP (or decrease in DBP) predicted a 13% increase in odds (or, respectively, a 14% decrease in odds) of verbal reasoning decline. Post-DBS patient classification using BMI and BP predictors yield a .882 specificity and a .857 sensitivity.  

 

Conclusions:
BMI, SBP, and DBP should be considered in predicting DBS surgical outcomes, particularly on verbal reasoning tasks. This small sample requires replication but is consistent with existing literature. 
10.1212/WNL.0000000000202249