Abstract
Purpose: :
To determine the relationship between body mass index (BMI) and ocular outcomes, including diabetic macular edema (DME) and visual acuity (VA) in patients with diabetes.
Methods: :
Retrospective structured query of the electronic medical records for all patients evaluated at both the BEI and the JDC endocrinology service from 1/1/06 to 10/31/08. Patients were grouped based on BMI classifications of the US National Health & Nutrition Examination Survey: under/normal weight (BMI <25), overweight/obese (BMI 25-35), and severe/morbidly obese (BMI > 35).
Results: :
A total of 12,372 records were reviewed and BMI data was available for 8,097 (65%) subjects. The cohort was predominantly white (66%), 52% male, and 54% type 2 DM (T2DM). Median age was 53.7y and median DM duration was 14.8y. Higher BMI was associated with older age (p<0.0001), male gender (p<0.0001), T2DM (p<0.0001), hypertension (p<0.0001), cardiac disease (p<0.0001), hypercholesterolemia (p<0.0001), and nephropathy (p<0.0001) but was not associated with HbA1c (p=0.59). Multivariable analysis adjusting for age, gender, DM duration, HbA1C, hypertension and lipid-lowering medications showed that in T1DM, higher BMI was associated with the presence of DME (p=0.048) but not with DR severity, laser treatment or VA outcomes. In T2DM, higher BMI was associated with worse VA but was unrelated to DR severity, presence of DME or laser treatment. Mean VA was better in T2DM patients with lower BMI (under/normal weight: 20/16, overweight/obese: 20/20-1, severe/morbidly obese: 20/20, p<0.0001). Furthermore, T2DM patients with lower BMI who received DME treatment had greater improvement in VA (under/normal weight: +3 letters, overweight/obese: +1 letter, severe/morbidly obese: -2 letters, N=268; p=0.006) over a median follow-up of 8.4 months (range 3-17 months).
Conclusions: :
In this predominantly white population, a higher BMI is associated with a higher rate of DME in T1DM, and worse visual acuity and less visual improvement following DME treatment in T2DM. These findings emphasize the importance of weight control for diabetic eye disease severity and treatment outcomes. Future studies should address the possible mechanisms by which BMI may affect DME treatment response in T2DM.
Keywords: diabetic retinopathy • clinical (human) or epidemiologic studies: risk factor assessment • edema