Impact of BMI on gonadorelin-stimulated LH peak in premenarcheal girls with idiopathic central precocious puberty.

OBJECTIVE: To clarify the impact of body mass index (BMI) on luteinizing hormone (LH) secretion in response to gonadorelin (GnRH) stimulation testing in girls diagnosed with idiopathic central precocious puberty (ICPP). METHODS: Retrospective single-center cohort study was carried out in 865 confirmed ICPP girls who underwent GnRH stimulation tests. Pubertal development according to Tanner, sex hormone parameters, and LH secretion in response to GnRH-stimulation was compared. RESULTS: Around 609 girls were of normal weight (70.4%), while 168 children (19.4%) were overweight, and 88 (10.2%) were obese. Peak LH levels after GnRH were much higher in the normal-weight group, with a median of 9.1 mIU ml(-1) (interquartile 5.2-13.1), compared with the median peak LH in the overweight and obese groups (8.5 mIU ml(-1), interquartile 5.3-11.6, and 6.2 mIU ml(-1), interquartile 5.3-11.0, respectively P < 0.001 for all comparisons). Peak LH/FSH ratio was also lower in the obese group (median 0.6, interquartile 0.68-0.90) compared with the normal-weight (median 0.8, interquartile 0.61-1.11) and overweight (median 0.8, interquartile 0.64-0.92) groups. CONCLUSIONS: Higher BMI is associated with lower LH response to GnRH-stimulation testing in girls with ICPP. It is recommended that BMI should be considered when interpreting GnRH-stimulation tests.

Changing epidemiology of metabolic syndrome and type 2 diabetes in Chinese youth.

China is gradually taking its place as one of the world's economic giants and concurrently learning to understand how to bear the burdens of diseases that are more common in the fully developed world, such as pediatric obesity, metabolic syndrome, and type 2 diabetes mellitus. The purpose of this review is to consolidate the available information regarding these and draw the focus toward their sequential progression and increasing prevalence in Chinese children. Studies were collected in both English and Chinese, and the data were reviewed on the basis of disease prevalence and risk factors that are known from scientific literature that has been published to date. The majority of studies with appropriate content for inclusion here have been conducted within the last 15 years and up to date information from recent local and international research has also been included. Several factors have been implicated for the rise in obesity, most notably, the progressing economic expansion and exposure of local Chinese populations to Western influences. With this, metabolic syndrome has become a growing concern, as it is a precursor to cardiovascular disease and type 2 diabetes, leading to the alarmingly rapid development of deleterious consequences in children. The International Diabetes Federation proposed a definition for metabolic syndrome in 2007 (MS-IDF2007) worldwide, but whether it is also suitable for the Chinese population remains uncertain, so we have created the Chinese definition of metabolic syndrome upon the IDF framework. This MS-CHN2012 definition is based on multicenter studies to simplify and standardize primary care screening methods and is the first of its kind in China. Juvenile type 2 diabetes is the most worrisome result of obesity and metabolic syndrome, and studies have shown that the prevalence has doubled within 5 years-surpassing the prevalence of juvenile type 1 diabetes. Because of the extremely low number of studies currently published on these topics in China, emphasis needs to be placed on the assessment of the health status of the population. Screening methods are imperative because lifestyle interventions can reduce and even reverse the pathologic consequences of this disease, if detected early.