The relationship between hand osteoarthritis and serum leptin concentration in participants of the Third National Health and Nutrition Examination Survey

Introduction: Leptin has been suspected to contribute to the development of osteoarthritis (OA). However, this hypothesis has not been tested in large-scale hand OA cohorts. Our study aimed to determine whether there is a cross-sectional relationship between serum leptin levels and hand OA in a population-based sample of US adults. Method: We used the Third National Health and Nutrition Examination Survey (NHANES III), a national cross-sectional population-based survey, to study the relationship between hand OA and serum leptin concentration. We applied previously established classification criteria for hand OA. Patients with rheumatoid arthritis were excluded. Potential confounders included sex, body mass index, the presence of polyarticular OA, diabetes, and total cholesterol. We estimated unadjusted mean leptin concentration by hand OA status and by all confounders. We further developed a linear regression model to assess mean leptin levels, adjusted for appropriate confounders. Results: Of 2,477 subjects in the NHANES III sample that had a hand examination and did not have rheumatoid arthritis, 1,056 (42.6%) had a leptin measurement and were included in the analysis. Subjects with and without leptin measurement had similar demographic characteristics. We did not find any significant differences in mean serum leptin levels in subjects with symptomatic hand OA (7.38 ng/ml in males (95% confidence interval (CI) = 5.31, 9.46) and 21.55 ng/ml in females (95% CI = 17.08, 26.02)), asymptomatic hand OA (6.69 ng/ml in males (95% CI = 5.19, 8.18) and 17.09 ng/ml in females (95% CI = 15.00, 19.18)), and no hand OA (8.22 ng/ml in males (95% CI = 7.47, 8.97) and 20.77 ng/ml in females (95% CI = 18.01, 23.53)) in the unadjusted analysis. In a multivariable linear regression model that included variables of hand OA status, age, race/ethnicity, and obesity status, we found no statistically significant association between serum leptin and hand OA status. Conclusions: In this cross-sectional study of a large representative US cohort, we did not find any evidence to support the hypothesis that serum leptin is associated with hand OA

Adipokine Hormones and Hand Osteoarthritis: Radiographic Severity and Pain

Introduction: Obesity's association with hand osteoarthritis cannot be fully explained by mechanical loading. We examined the relationship between adipokines and radiographic hand osteoarthritis severity and pain. Methods: In a pilot study of 44 hand osteoarthritis patients (39 women and 5 men), serum adipokine concentrations and hand x-ray Kallman-scores were analyzed using linear regression models. Secondary analyses examined correlates of hand pain. Results: The cohort had a mean age of 63.5 years for women and 72.6 for men; mean (standard deviation) Kallman-scores were 43.3(17.4) for women and 46.2(10.8) for men. Mean body-mass-index was 30 kg/m2 for women and men. Mean leptin concentration was 32.2 ng/ml (women) and 18.5 ng/ml (men); mean adiponectin-total was 7.9 ng/ml (women) and 5.3 ng/ml (men); mean resistin was 7.3 ng/ml (women) and 9.4 ng/ml (men). No association was found between Kallman-scores and adipokine concentrations (R2 = 0.00–0.04 unadjusted analysis, all p-values>0.22). Secondary analyses showed mean visual-analog-scale pain of 4.8(2.4) for women and 6.6(0.9) for men. Leptin, BMI, and history of coronary artery disease were found to be associated with visual-analog-scale scores for chronic hand pain (R2 = 0.36 unadjusted analysis, p-values≤0.04). Conclusion: In this pilot study, we found that adipokine serum concentrations were not associated with hand osteoarthritis radiographic severity; the most important correlates of joint damage were age and disease duration. Leptin serum concentration, BMI, and coronary artery disease were associated with the intensity of chronic hand OA pain

Demographics, Disease Characteristics, and Adipokine Serum Concentrations of Study Participants Categorized by Gender.

<p>Notes: BMI, body mass index. MW, molecular weight.</p>*<p>Data summarized from participants who entered secondary analysis of adipokines and pain (35 women and 5 men).</p

Unadjusted and Adjusted Analyses of Hand X-ray Kallman Score as a Function of Each Adipokine and Significant Determinants.

<p>Notes: In adjusted analyses, we retained only gender, history of coronary artery disease, thyroid disease, and diabetes mellitus, and the statistically significant covariates (age, disease duration), selected during model building as defined by p<0.10. Unadjusted linear regression analysis was not performed in male participants due to the small sample size (N = 5). HMW, High Molecular Weight. MMW, Middle Molecular Weight. β refers to the beta coefficient estimated in linear regression models. SE, standard error.</p>¶<p>With adipokine serum concentrations not forced into the models, and adjusted for gender, history of coronary artery disease, thyroid disease, and diabetes mellitus, only age and osteoarthritis disease duration were associated with Kallman scores, while history of coronary artery disease, thyroid disease, diabetes mellitus, and gender were insiginificant, as defined by p-value>0.05.</p

Unadjusted and Adjusted Linear Regression Analyses of Pain as a Linear Function of Each Adipokine and Significant Determinants.

<p>Notes: In adjusted analyses, we retained only gender, history of coronary artery disease, thyroid disease, and diabetes mellitus, and the other significant covariates selected during model building as defined by p value<0.10. Unadjusted linear regression analysis was not performed in male participants due to the small sample size (N = 5). HMW, High Molecular Weight. MMW, Middle Molecular Weight. BMI, body mass index. VAS, visual-analog-scale. β refers to the beta coefficient estimated in linear regression models. SE, standard error.</p>¶<p>With adipokine serum concentrations not forced into the models, adjusted for gender, history of coronary artery disease, thyroid disease, and diabetes mellitus, we found leptin, BMI, history of coronary artery disease were associated with pain, while thyroid disease, diabetes mellitus, and gender were insiginificant, as defined by p-value>0.05.</p