Inverse Association Between Serum Osteoprotegerin and Bone Mineral Density in Renal Transplant Recipients

Serum Irisin Level Is Positively Associated with Bone Mineral Density in Patients on Maintenance Hemodialysis

BACKGROUND

Irisin is a circulating hormone-like myokine that plays an important role in bone metabolism. We performed a cross-sectional study to investigate whether serum irisin levels correlated with bone mineral density (BMD) in patients on maintenance hemodialysis (MHD).

METHODS

Blood samples were obtained from 80 patients on MHD, and serum irisin concentrations were determined using a commercially available enzyme-linked immunosorbent assay. BMD was measured by dual-energy X-ray absorptiometry of the L2-L4 vertebrae.

RESULTS

In the study cohort, 10 (12.5%) and 19 (23.8%) patients had osteoporosis and osteopenia, respectively, and 51 (63.75%) patients had normal BMD. Lumbar T-score was negatively associated with body height (P=0.010), body weight (P=0.002), body mass index (BMI, P=0.010), and serum irisin (P < 0.001) and was positively associated with advanced age (P=0.031), female sex (P=0.001), alkaline phosphatase (ALP, P=0.010), urea reduction rate (P=0.018), and fractional clearance index for urea (P=0.020). Multivariable forward stepwise linear regression analysis revealed that high serum logarithmically transformed irisin (log-irisin, β = 0.450, adjusted R 2 change = 0.258; P < 0.001), female sex (β = -0.353, adjusted R 2 change = 0.134; P < 0.001), and serum ALP level (β = -0.176, adjusted R 2 change = 0.022; P=0.049) were significantly and independently associated with lumbar BMD in patients on MHD.

CONCLUSIONS

In addition to female sex and serum ALP level, serum irisin level was positively associated with lumbar BMD in patients on MHD.

Bone mineral density in older patients with chronic heart failure is related to NYHA classification: a retrospective study

PURPOSE

Discrepant results on relationship between chronic heart failure (CHF) and bone mineral density (BMD) have been reported and little has investigated the association between bone mass loss and New York Heart Association (NYHA) classification in CHF patients. This study aimed to assess whether BMD was associated with NYHA classification in older CHF patients.

METHODS

It was a retrospective study and included 1049 stable CHF patients aged over 60 years in Zhejiang Hospital. BMD and T-score at femoral neck (FN) and lumbar spines over L2-L4 regions were measured using Dual-Energy X-ray Absorptiometry. One-way ANOVA was used to compare continuous data of different NYHA functional class. Categorical variables were compared by Chi-square analysis. Pearson or Spearman correlation test was used to analyze the association between BMD and NYHA class, clinical parameters, lab data, etc. Significant variables in the correlation test (P < 0.05) were then tested by a multivariate linear regression test with stepwise subset selection to identify independent factors predicting BMD.

RESULTS

There were significant differences in FN BMD and T score across NYHA class I-IV, and that L2-L4 BMD and T score in patients in NYHA class IV were significantly lower when compared with CHF participants in NYHA classes I, II, and III. Moreover, Pearson correlation test and multivariate linear regression test demonstrated that there were statistically significant correlations between bone densitometric parameters and NYHA class.

CONCLUSIONS

There was a significant correlation between BMD and T-score at lumbar spines over L2-L4 and FN and NYHA class, implying that early screening and comprehensive intervention for osteoporosis (OP) might be helpful for patients with CHF.