Relationship of serum leptin and 25-hydroxyvitamin D in knee osteoarthritis patients

Abstract

Background : Osteoarthritis (OA) is a degenerative articular disease that involves progressive alterations in all joint structures resulting from aging and overuse activity. Leptin and vitamin D play a crucial role in energy metabolism; however, few reports on leptin and 25-hydroxyvitamin D (25(OH)D) in knees of osteoarthritis (OA) has been known.

Objectives : To examine serum levels of leptin and vitamin D in knee OA patients and analyze the possible relationship between serum leptin, 25-hydroxyvitamin D, and clinical parameters in OA patients.

Methods : In a cross-sectional study, 235 adult patients (212 women and 23 men, aged 65.6  6.5 years) with established diagnosis of OA and 50 healthy controls were recruited. Serum 25(OH)D and serum leptin levels were
measured.

Results : Serum vitamin D insufficiency ( 30 ng/ml) was found in 48.0% of the patients with OA; whereas serum vitamin D deficiency ( 20 ng/ml) was detected in 35.0% of osteoarthritis patients. Serum leptin concentrations were significantly elevated in OA patients when compared with the controls (P = 0.02). There was a negative correlation between serum 25(OH)D concentration and serum leptin in patients with knee OA (P < 0.001) (r = -0.26, P < 0.001).

Conclusions : Vitamin D insufficiency and deficiency is highly prevalent in OA patients and associated with higher serum leptin. These findings suggest that high serum leptin could be used for predicting low vitamin D in knee
OA patients.