Association of body mass index with longitudinal rates of retinal atrophy in multiple sclerosis

Mult Scler. 2020 Jun;26(7):843-854. doi: 10.1177/1352458519900942. Epub 2020 Apr 16.

Abstract

Background: Studies evaluating associations between body mass index (BMI) and optical coherence tomography (OCT) measures in multiple sclerosis (MS) are lacking.

Objective: To assess whether elevated BMI is associated with accelerated retinal atrophy.

Methods: In this observational study, 513 MS patients were followed with serial spectral-domain OCT for a median of 4.4 years. Participants were categorized as normal weight (BMI: 18.5-24.9 kg/m2), overweight (BMI: 25-29.9 kg/m2), and obese (BMI: ⩾30 kg/m2). Participants with diabetes mellitus or uncontrolled hypertension and eyes with optic neuritis (ON) ⩽6 months prior to baseline OCT or during follow-up were excluded. Statistical analyses were performed with mixed-effects linear regression.

Results: Obese patients (n = 146) exhibited accelerated rates of ganglion cell + inner plexiform layer (GCIPL) atrophy relative to normal weight patients (n = 214; -0.57%/year (95% confidence interval (CI): -0.65% to -0.48%) versus -0.42%/year (95% CI: -0.49% to -0.35%); p = 0.012). GCIPL atrophy rate did not differ between overweight (n = 153) and normal weight patients (-0.47%/year vs -0.42%/year; p = 0.41). Each 1 kg/m2 higher BMI was associated with accelerated GCIPL (-0.011%/year; 95% CI: -0.019% to -0.004%; p = 0.003) atrophy. Multivariable analyses accounting for age, sex, race, MS subtype, and ON history did not alter the above findings.

Conclusions: Elevated BMI, in the absence of overt metabolic comorbidities, may be associated with accelerated GCIPL atrophy. Obesity, a modifiable risk factor, may be associated with accelerated neurodegeneration in MS.

Keywords: Multiple sclerosis; body mass index; optical coherence tomography; retina.

Publication types

  • Observational Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Atrophy / pathology
  • Body Mass Index*
  • Comorbidity
  • Disease Progression*
  • Female
  • Humans
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Multiple Sclerosis / diagnostic imaging
  • Multiple Sclerosis / epidemiology
  • Multiple Sclerosis / pathology*
  • Obesity / epidemiology
  • Overweight* / epidemiology
  • Retina / diagnostic imaging
  • Retina / pathology*
  • Tomography, Optical Coherence