Nitric oxide and pro-inflammatory cytokine serum levels in postmenopausal women with the metabolic syndrome

Abstract

Background: The metabolic syndrome (METS) increases after the menopause which may enhance cardiovascular risk in part explained by a pro-inflammatory state. Objective: Measure nitric oxide (NO), tumor necrosis factor-alpha (TNF-α) and interleukin 6 (IL-6) serum levels in postmenopausal women with and without the METS (Adult Treatment Panel III criteria). Methods: Analyte levels were compared among those with and without the syndrome and each of its diagnostic components. Rho Spearman coefficients were also calculated to determine correlations between analyte levels and various numeric variables. Results: Median age of all studied women (n = 88) was 54.4 years, 62.5% had abdominal obesity, 14.8% hyperglycemia, 59.1% high triglycerides (TG) and 44.3% hypertension. Women with the METS (n = 44) displayed higher body mass index values and higher rates of abdominal obesity, hyperglycemia, hypertriglyceridemia, hypertension and low HDL-C levels. Median NO and IL-6 levels were significantly higher in women with the METS as compared to controls (p < 0.05). Independent of presenting the METS, analytes were higher in those displaying abdominal obesity (IL-6), hypertension (IL-6 and TNF-α) and more METS diagnostic criteria and abnormal HDL-C, TG and glucose levels (NO). Both cytokines positively correlated with the number of METS criteria, age and time since menopause, IL-6 positively with waist circumference and TNF-α positively with blood pressure levels. NO levels inversely correlated with HDL-C values and positively with the number of METS criteria, glucose, and TG levels; correlation with the latter being the highest (r² = 0.65, p = 0.0001). Conclusion: Postmenopausal women with the METS displayed higher IL-6 and NO levels, with significant correlations found between studied analytes and some of the components of the syndrome.

Keywords::

• Cytokines
• inflammation
• interleukin 6
• metabolic syndrome
• nitric oxide
• obesity
• postmenopause
• tumor necrosis factor-α

Acknowledgements

The authors would like to thank women who participated in this study.

Declaration of Interest: This research has been supported by the Universidad Católica de Santiago de Guayaquil, Ecuador through grant No. SIU-3373-2011 (OMEGA Project 2011) provided by the Sistema de Investigación y Desarrollo.