Establishing international optimal cut-offs of waist-to-height ratio for predicting cardiometabolic risk in children and adolescents aged 6-18 years.

BACKGROUND: Waist-to-height ratio (WHtR) has been proposed as a simple and effective screening tool for assessing central obesity and cardiometabolic risk in both adult and pediatric populations. However, evidence suggests that the use of a uniform WHtR cut-off of 0.50 may not be universally optimal for pediatric populations globally. We aimed to determine the optimal cut-offs of WHtR in children and adolescents with increased cardiometabolic risk across different countries worldwide. METHODS: We used ten population-based cross-sectional data on 24,605 children and adolescents aged 6-18 years from Brazil, China, Greece, Iran, Italy, Korea, South Africa, Spain, the UK, and the USA for establishing optimal WHtR cut-offs. We performed an external independent test (9,619 children and adolescents aged 6-18 years who came from other six countries) to validate the optimal WHtR cut-offs based on the predicting performance for at least two or three cardiometabolic risk factors. RESULTS: Based on receiver operator characteristic curve analyses of various WHtR cut-offs to discriminate those with ≥ 2 cardiometabolic risk factors, the relatively optimal percentile cut-offs of WHtR in the normal weight subsample population in each country did not always coincide with a single fixed percentile, but varied from the 75th to 95th percentiles across the ten countries. However, these relatively optimal percentile values tended to cluster irrespective of sex, metabolic syndrome (MetS) criteria used, and WC measurement position. In general, using ≥ 2 cardiometabolic risk factors as the predictive outcome, the relatively optimal WHtR cut-off was around 0.50 in European and the US youths but was lower, around 0.46, in Asian, African, and South American youths. Secondary analyses that directly tested WHtR values ranging from 0.42 to 0.56 at 0.01 increments largely confirmed the results of the main analyses. In addition, the proposed cut-offs of 0.50 and 0.46 for two specific pediatric populations, respectively, showed a good performance in predicting ≥ 2 or ≥ 3 cardiometabolic risk factors in external independent test populations from six countries (Brazil, China, Germany, Italy, Korea, and the USA). CONCLUSIONS: The proposed international WHtR cut-offs are easy and useful to identify central obesity and cardiometabolic risk in children and adolescents globally, thus allowing international comparison across populations.

Clinical correlates of persistently elevated liver enzymes in type 2 diabetic outpatients.

AIMS: To evaluate the prevalence and the clinical implication of persistently elevated liver enzymes in diabetic subjects, with no evidence of viral hepatitis infection or alcohol abuse. METHODS: Clinical, lifestyle, anthropometric data and laboratory test values were collected in 916 type 2 diabetic subjects, examined for alanine aminotransferase (ALT), aspartate aminotransferase (AST) and γ-glutamyltranspeptidase (γ-GT) levels at two different time points. RESULTS: Five hundred forty four patients (59.4%) showed normal (NLT group) and 182 (19.9%) persistently elevated (ELT group) liver tests in both determinations. ELT patients were prevalently men (P=0.016), younger (P<0.0001) and with a lower duration of diabetes (P=0.008). Adjusting for age and sex, ELT subjects had significantly higher BMI (P<0.001), waist circumference (P=0.010), systolic (P=0.017) and diastolic blood pressure (P<0.001), and higher levels of fasting blood glucose (P=0.023), and triglycerides (P<0.0001). Current hypoglycemic and/or hypolipidemic drugs were comparable between the two groups. At multivariate analysis, male gender (OR=3.017, P=0.012), worse metabolic control (HbA1c, OR=1.408, P=0.017), and a younger age (OR=1.054, P=0.007) predicted the presence of persistently elevated liver enzymes. CONCLUSIONS: Persistently elevated liver enzymes are a common finding in outpatient type 2 diabetic subjects, particularly in young men with suboptimal metabolic control and with the features of metabolic syndrome. The persistence of abnormal liver tests may be of potential utilization in clinical practice for the screening of patients at high risk of NAFLD.