Study: BMI, smoking and metabolic factors are associated with knee pain
Increased BMI, current smoking status and glycemic control are modifiable risk factors associated with self-reported knee pain, according to published results.
In a retrospective, cross-sectional study, Daniel A. Charen, MD, and colleagues from the Icahn School of Medicine at Mount Sinai and University of Pittsburgh Medical Center used a 5-year sample (1999 to 2004) of the National Health and Nutrition Examination Survey database to analyze modifiable cardiometabolic risk factors in 3,144 patients with knee pain.
According to the study, knee pain was self-reported by patients without radiographic confirmation to include a more comprehensive total knee pain cohort. Risk factors included cardiometabolic characteristics, such as BMI and glycohemoglobin (HbA1c), as well as patient factors, such as age, race, poverty, gender and smoking status. Glycemic control was determined using a threshold of HbA1c greater than 6.5%.
Compared with those with no reported knee pain, patients with knee pain tended to be older, female, white and former smokers with a lower poverty to income ratio, higher BMI and elevated HbA1c, according to the study.
Researchers ultimately determined that modifiable risk factors associated with increased odds of knee pain were obesity (OR 1.54), glycemic control (OR 1.20) and current smoker (OR 1.15). From subgroup analysis, they also determined the risk of knee pain was doubled in patients aged 65 years and older (OR 1.09) compared with patients younger than 65 years (OR 1.06).
Charen and colleagues concluded the “significant association between knee pain and glycemic control, BMI and smoking may be related to an increased prevalence of the metabolic subtype of osteoarthritis in these patients.”
“This subtype is defined by the presence of metabolic syndrome, adipokines, hyperglycemia, hormonal imbalance and presence in middle-aged people,” they wrote in the study.
“Despite these associations, emphasis should still be placed on determining a biomechanical etiology for a patient’s knee pain for guiding management,” Charen and colleagues wrote. “That being said, lifestyle modifications of weight loss, diabetes control and smoking cessation may be useful adjuncts in the armamentarium of physicians when providing conservative treatment options for patients.”