Peptide Levels In Women Research Articles

Reply: The Association between Obstructive Sleep Apnea Severity and N-Terminal Pro–B-Type Natriuretic Peptide Levels in Women

From the Authors: We appreciate Dr. Mirrakhimov’s and Dr. Lin’s comments regarding our article in the Journal (1) studying the association between obstructive sleep apnea (OSA) and serum high-sensitivity troponin (hs-TnT) and N-terminal pro B-type natriuretic peptide (NT-proBNP) in 1,645 community-dwelling subjects free of coronary heart disease and heart failure from the intersection between the Atherosclerosis Risk in the Communities (ARIC) and the Sleep Heart Health Study (SHHS). We agree with Dr. Mirrakhimov that our study’s finding may not be generalizable to persons of nonwhite race/ethnicity. As with most previous studies evaluating the relationship between OSA and biomarkers of myocardial injury, the population participating in both ARIC and SHHS was predominantly white. To the best of our knowledge, despite findings of significant race-related differences in the sleep architecture and OSA symptoms (2), there is a lack of robust data on the cardiovascular implications of OSA in several ethnic populations, in particular Hispanics (3). Further studies will be necessary to elucidate whether the association between hs-TnT and OSA severity is also applicable to other ethnic populations and to clarify the cardiovascular implications of OSA more generally in these understudied populations. In this respect, several ongoing NHLBI cohort studies, including the Jackson Heart Study in African Americans (4) and the Study of Latinos (5), offer a unique potential opportunity. Dr. Lin’s letter raises the possibility that the negative association between NT-proBNP and OSA severity noted in our unadjusted analysis may be confounded by the differential distribution of sex by OSA severity. We agree with Dr. Lin that there are important sex-based differences in both the pathophysiology of OSA (6) and the cardiac response to insult and altered loading conditions (7). In our study, the association between OSA and NT-proBNP remained negative and strongly significant (P = 0.007), even after adjusting for sex and age. After further adjusting for body mass index, this association was no longer significant (P = 0.05). Similarly, in our dataset, sex did not modify the association between respiratory disturbance index and NT-proBNP level (P for interaction = 0.21). An exploratory sex-stratified analysis found a negative association in women of marginal significance (P = 0.05) and a null association in men. Our findings indicate a need for further research to address potential sex differences in cardiovascular biomarker responses to OSA-related stresses.

The Association between Obstructive Sleep Apnea Severity and N-Terminal Pro–B-Type Natriuretic Peptide Levels in Women

The Association between Obstructive Sleep Apnea Severity and N-Terminal Pro–B-Type Natriuretic Peptide Levels in Women

Serum calcitonin gene-related peptide levels in women with polycystic ovary syndrome

Calcitonin gene-related peptide (CGRP) is an amino acid neuropeptide with widespread expression. It has potent effects on lipid and energy metabolism. It induces insulin resistance. This study was planned to determine CGRP levels in women with polycystic ovary syndrome (PCOS). Forty-seven women with PCOS and 34 healthy controls were evaluated in this controlled clinical study. Serum lipid sub-fractions, postprandial and fasting glucose, insulin and other hormones (gonadotropins, androgens) and CGRP levels were measured. Homeostasis model assessment (HOMA-IR) was used to estimate insulin resistance. Waist measurements, postprandial and fasting glucose and fasting insulin levels and free androgen index and HOMA-IR were significantly higher in subjects with PCOS. However, the women with PCOS had considerably lower high-density lipoprotein cholesterol levels than healthy subjects. Serum CGRP levels were higher in study subjects than in controls, although it was statistically insignificant. Serum CGRP level was not related with insulin resistance, ovarian hyperandrogenism and dyslipidemia in abdominally obese women with PCOS. These outcomes propose that CGRP may not play a pivotal role in the pathogenesis of PCOS.

Effects of transdermal testosterone on natriuretic peptide levels in women: a randomized placebo-controlled pilot study

To investigate whether testosterone administration alters natriuretic peptide levels in women. Three-month, double-blind, randomized, placebo-controlled study. Clinical research center. Fifty-one women with hypoandrogenemia due to hypopituitarism. Transdermal testosterone (300 μg daily) or placebo patch. N-Terminal pro-B-type natriuretic peptide (NT-proBNP) levels. NT-proBNP levels decreased in the transdermal testosterone group compared with placebo over three months. The difference between groups remained significant after controlling for baseline age, systolic blood pressure, body mass index, and homeostasis model assessment of insulin resistance. Change in NT-proBNP over 3 months was inversely associated with change in free testosterone levels. Testosterone administration to women results in decreased natriuretic peptide levels, suggesting that testosterone may be an inverse regulator of the natriuretic peptide system. NCT00027430.

Effects of oral contraceptives on natriuretic peptide levels in women with hypothalamic amenorrhea: a pilot study

Natriuretic peptides, which are important regulators of salt handling and blood pressure, are 60%-75% higher in healthy young women than in men, consistent with a gender dimorphism. In this randomized, placebo-controlled study in women with functional hypothalamic amenorrhea, we show that administration of oral contraceptives (OC) increases natriuretic peptide levels and that end-of-study free T levels are inversely associated with amino-terminal pro-B-type natriuretic peptide levels, consistent with the hypothesis that natriuretic peptide levels may be mediated by differences in gonadal steroid concentrations-estrogens (E) or androgens.

Urinary peptide levels in women with eating disorders. A pilot study.

The aim of this study was to evaluate whether the urinary excretion of low molecular weight peptides is increased in women with a history of anorexia nervosa/self starvation. The study group consisted of 12 women aged 20-38 years who were treated in a specialised day care unit for eating disorders in Stockholm between January and December 1998; the controls were eight women with primary bulimia treated in the same unit (A) and ten healthy women without any eating disorder (B). The chromatographically measured urinary peptide levels in the study group were significantly higher than those in control group A (and B when one highly influential individual with very low peptide excretion in the study group was excluded from the analyses). These findings offer some support to the speculative hypothesis that eating disorder symptoms may be linked to increased levels of neuroactive peptides, although it is necessary to define the peptides further before any definite conclusion can be drawn. Furthermore, the study group was characterised by many interpersonal differences in eating behaviour that could explain the increased urinary peptide levels.

C-Type natriuretic peptide levels in women with gestational hypertension and preeclampsia

Objective: To measure plasma levels of C-type natriuretic peptide in women with normal pregnancies and those complicated by gestational hypertension and preeclampsia. Methods: We collected venous plasma samples from 20 women with normal pregnancies, 15 with gestational hypertension, and nine with preeclampsia. Gestational ages ranged from 26–39 weeks. We measured C-type natriuretic peptide concentrations by radioimmunoassay. Statistical comparisons were made by one-way analysis of variance and Tukey test. Results: The mean plasma concentration of C-type natriuretic peptide in the women with normal pregnancy was 7.1 ± 2.5 pg/mL, in those with gestational hypertension 9.6 ± 4.2 pg/mL, and in those with preeclampsia 8.1 ± 2.4 pg/mL. There were no statistically significant differences between groups. The statistical power to detect a difference of 3 pg/mL at the 5% significance level was 78% for the group with gestational hypertension and 64% for the preeclamptic group. Conclusion: Our results suggest that C-type natriuretic peptide plasma levels are not significantly different in normal pregnancies and those complicated by gestational hypertension or preeclampsia. In hypertensive pregnancy disorders, C-type natriuretic peptide showed a distinct course compared with atrial natriuretic peptide and brain natriuretic peptide.