What is the Impact of Body Mass Index on Cardiovascular and Musculoskeletal Health?

Obesity has become a major public health concern over the past several decades and has been shown to be associated with type 2 diabetes, cardiovascular diseases, dyslipidemia, hypertension, osteoarthritis (OA), and certain types of cancer. The impact of excess weight on cardiovascular and musculoskeletal health is not well-summarized in the literature, and there are some contradictory reports. Therefore, the purpose of this study was to assess the impact of body mass index (BMI) on: 1) cardiovascular outcomes; 2) osteoarthritis risk and progression; and 3) total knee arthroplasty outcomes (TKA). Three literature searches were performed to identify clinical studies that assessed how BMI affects cardiovascular and musculoskeletal health. We included reports published within last five years. A total of 138 studies on cardiovascular health and 140 studies on musculoskeletal health were identified. After reviewing the abstracts and related citations from the references, there were 29 studies included in the present study. The effect of varying levels of BMI have demonstrated a relationship to cardiovascular disease, osteoarthritis, and TKA outcomes. The evidence suggests that as BMI increases, the chance of developing cardiovascular disease, OA, and negative TKA outcomes also increases. Furthermore, there appears to be a negative effect with being underweight on outcomes as well, suggesting that being at "normal" weight may optimize outcomes. However, there are several reports which make these findings more complicated. Several beneficial factors associated with higher BMI include increased muscle mass and strength, which can potentially be beneficial through better cardiorespiratory fitness or hormonal effects. Additionally, several studies suggest that improving fitness is more important than intentional weight loss for cardiovascular health and osteoarthritis. Therefore, future studies are warranted to assess the combination of BMI and activity to assess the optimal balance and how they affect cardiovascular and musculoskeletal outcomes.