Serum adipokines as biomarkers of beta-cell function in patients with type 1 diabetes: positive association with leptin and resistin and negative association with adiponectin. Leptin and adiponectin levels in patients with ankylosing spondylitis. The effect of infliximab treatment.
BACKGROUND We investigated the adipokines adiponectin , leptin and resistin as serum biomarkers of beta-cell function in patients with type 1 diabetes . METHODS One hundred and eighteen patients with type 1 diabetes ( 20.3 ± 7.5 years ) diagnosed < 5 years underwent st and ardized mixed meal test ( MMTT ) for 2 h.  Systemic concentrations of C-peptide , adiponectin , leptin and resistin obtained during MMTT were measured and compared between patient groups by multiple regression analysis . RESULTS Patients were divided by their adipokine levels in subgroups above or below the median level ( ' high versus low ' ) . High adiponectin levels ( > 10.6 µg/mL ) were associated with lower C-peptide compared to the low adiponectin subgroup ( p < 0.03 ) . Increased leptin or resistin concentrations associated positively with beta-cell function even after adjustment for metabolic confounders ( p < 0.04 ) . The described associations between adipokines and C-peptide concentrations persisted in Spearman correlation tests ( p < 0.05 ) . Serum adipokines fell during MMTT ( p < 0.05 ) . CONCLUSIONS Serum adipokine levels differentially correlate with beta-cell function in type 1 diabetes independent of BMI or metabolic control . Serum adipokines should be investigated as biomarkers of beta-cell function in prospect i ve studies and intervention trials in type 1 diabetes BACKGROUND Adipose tissue-derived leptin and adiponectin control hunger , energy expenditure , insulin sensitivity , endothelial function , reproduction and immunity and are thought to play a role in autoimmune diseases . However , their role in ankylosing spondylitis ( AS ) is not clearly defined . Tumour necrosis factor ΤNF-α is a potential modulator of adipocytokines . The effect of longterm anti-TNF-α treatment on plasma levels of leptin and adiponectin has not been assessed so far . OBJECTIVES To assess the effect of a 6-month anti-TNF-α treatment on serum leptin and adiponectin levels in AS patients . METHODS Thirty men with AS were included in the study . Thirty age- and weight-matched men served as controls . Clinical and biochemical parameters were assessed and serum levels of leptin and adiponectin were measured with enzyme immunoassay methods prior to and after the 6-month treatment with infliximab . RESULTS Mean age and disease duration of AS patients were 40.6±13.7 and 13.4±8.4 years , respectively . At baseline , AS patients exhibited significantly higher adiponectin ( 15.4±8.3 vs. 8.6±4.2 μg/ml , p<0.05 ) , but no difference in leptin levels ( 7.2±2.9 vs. 8.9±6.4 ng/ml , p = NS ) . Adipocytokines did not correlate with any disease parameter . Body weight of the patients did not change significantly over the 6-month period . Serum levels of leptin and adiponectin did not change significantly after the 6-month treatment . CONCLUSIONS Adiponectin levels were significantly higher in AS patients compared with  controls . Infliximab treatment did not change serum levels of leptin and adiponectin suggesting that the anti-TNF-α treatment may not modulate significantly their levels
Subgroup analyses suggested that Asian and African AS patients as well as patients aged < 40 years had higher serum leptin and resistin levels when compared to controls .
Serum adiponectin levels were higher in AS patients compared to controls in subgroup of age ≥ 40 , and serum resistin levels in subgroup of BMI ≥ 25 .
Measurement method was a source of heterogeneity for resistin .
Publication bias was not observed and the robustness of study results was confirmed by sensitivity analysis .
Conclusion : Serum resistin , but not leptin or adiponectin levels may be closely associated with the development of AS .
HighlightsSerum levels of resistin are associated with the pathogenesis of AS.In specific subgroups , leptin and adiponectin may be related to AS.Measuring type is one of sources of heterogeneity for the studies about resistin
Objectives : Various studies have research ed the serum levels of leptin , adiponectin and resistin in patients with ankylosing spondylitis ( AS ) , but the results were inconclusive .
The purpose of this study was to systematic ally evaluate the correlations between serum levels of these adipokines and AS .