Age-specific reference ranges of serum anti-müllerian hormone in healthy women and its application in diagnosis of polycystic ovary syndrome: a population study.

OBJECTIVE: To establish the age-specific centiles of serum anti-müllerian hormone (AMH) levels in Chinese women, and to explore the use of multiples of median (MoM) AMH levels for the diagnosis of polycystic ovary syndrome (PCOS). DESIGN: An observational study. SETTING: University-affiliated hospitals and community clinics. POPULATION: We included 3137 healthy women aged 20-44 years recruited prospectively or who had archived serum samples from previous research projects. Another validation cohort of 751 women with PCOS as well as ovulatory controls, which was a convenient sample of women attending for infertility or menstrual disorders, was also studied. METHODS: The serum samples were assayed for AMH by the automated Access AMH assay. MAIN OUTCOME MEASURES: Age-specific reference ranges were constructed on the primary cohort with the Lambda-Mu-Sigma method. The MoM AMH of each subject in the validation cohort was calculated. RESULTS: Centile curves of serum AMH level against age were established. MoM AMH was significantly higher in women with PCOS than in controls (P < 0.05). The area under the ROC curve was 0.852 (95% confidence interval [CI] 0.825-0.877) (P < 0.0001) for discriminating women with PCOS from ovulatory controls by MoM AMH. CONCLUSIONS: We established a set of year-by-year age-specific reference ranges of serum AMH levels in Chinese women. The MoM AMH derived from this set of reference ranges is a promising tool to replace antral follicle count in the diagnosis of PCOS. TWEETABLE ABSTRACT: A set of age-specific reference ranges of AMH levels was established in Chinese women. Multiples of median AMH may be used to diagnose PCOS.

Foetal exposure to maternal passive smoking is associated with childhood asthma, allergic rhinitis, and eczema.

OBJECTIVE: We examined the hypothesis that foetal exposure to maternal passive smoking is associated with childhood asthma, allergic rhinitis, and eczema. METHODS. The study was a population-based cross-sectional survey of Hong Kong Chinese children aged ≤14 years carried out in 2005 to 2006. RESULTS. Foetal exposure to maternal passive smoking was significantly associated with wheeze ever (OR 2.05; 95% CI 1.58-2.67), current wheeze (OR 2.06; 95% CI 1.48-2.86), allergic rhinitis ever (OR 1.22; 95% CI 1.09-1.37), and eczema ever (OR 1.61; 95% CI 1.38-1.87). Foetal exposure to maternal active smoking was significantly associated with asthma ever (OR 2.10; 95% CI 1.14-3.84), wheeze ever (OR 2.46; 95% CI 1.27-4.78), and current wheeze (OR 2.74; 95% CI 1.24-6.01) but not with allergic rhinitis ever (OR 1.01; 95% CI 0.70-1.46) or eczema ever (OR 1.38; 95% CI 0.87-2.18). The dose response relationship between wheeze ever and current wheeze with increasing exposure, from no exposure to maternal passive smoking and then to maternal active smoking, further supports causality. CONCLUSION. There is significant association between foetal exposure to maternal passive smoking and maternal active smoking with childhood asthma and related atopic illnesses. Further studies are warranted to explore the potential causal relationship.

Parity and the metabolic syndrome in older Chinese women: the Guangzhou Biobank Cohort Study.

OBJECTIVE: To examine whether parity or gravidity contributes to the development of the metabolic syndrome (MS). METHODS: The first phase of the Guangzhou Biobank Cohort Study recruited 7352 women and 3065 men aged 50-93 years in 2003-4. Data on the number of live births and pregnancies, other reproduction-associated factors and socioeconomic and lifestyles factors were collected by standardized interview. The MS components were determined through physical examination and measurement of fasting blood samples. MS was identified if waist circumference was >or= 90 cm for men or >or= 80 cm for women, plus any two of: (a) raised triglyceride (TG) level (1.7 mmol/l) or specific treatment for this lipid abnormality; (b) reduced high density lipoprotein (HDL)-cholesterol (< 1.03 mmol/l in males or < 1.29 mmol/l in females) or specific treatment for this lipid abnormality; (c) raised blood pressure (BP, systolic BP >or= 130 mmHg or diastolic BP >or= 85 mmHg) or hypertension therapy; and (d) raised fasting glucose (>or= 5.6 mmol/l) or previously diagnosed type 2 diabetes. RESULTS: Before adjustment for potential confounders, we found associations between the number of births and lifestyle and socioeconomic factors in both sexes. However, in women, but not in men, body mass index (BMI), waist-hip ratio, triglyceride and glucose were positively associated with the number of birth after adjusting for a range of potential confounders. The age-adjusted prevalence of the MS increased with the number of births and pregnancies in women, but the gradient for birth was steeper than that for pregnancies [odds ratio change per birth 1.16, 95% confidence interval (CI) 1.11-1.22, P < 0.001; odds ratio change per pregnancy 1.11, 95% CI 1.06-1.16, P < 0.001], although attenuating the association adjustment did not affect the significance of these findings. There was no association in men with regard to the number of their partners' live births given the same analysis and similar shared living background with the women. CONCLUSION: Higher parity or gravidity was associated with a consistent increase in the risk of MS in Chinese women. As the association persisted after adjustment for lifestyle factors and there was no association between the risk of MS and the number of births associated with the partners of the males, the association in women may represent a biological response to pregnancy.