A Population‐Based Twin Study on Sleep Duration and Body Composition

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/93648/1/oby.2011.274.pd

Tracking Blood Glucose and Predicting Prediabetes in Chinese Children and Adolescents: A Prospective Twin Study

We examined the tracking of blood glucose, the development of prediabetes, and estimated their genetic contributions in a prospective, healthy, rural Chinese twin cohort. This report includes 1,766 subjects (998 males, 768 females) aged 6–21 years at baseline who completed a 6-year follow-up study. Oral glucose tolerance test was performed for all subjects at both baseline and follow-up. We found that subjects with low fasting plasma glucose (FPG) or 2 h post-load glucose (PG) levels at baseline tended to remain at the low level at follow-up. Subjects in the top tertile of baseline plasma glucose tended to have a higher risk of developing prediabetes at follow-up compared to the low tertile: in males, 37.6% vs. 27.6% for FPG and 37.2% vs. 25.7% for 2hPG, respectively; in females, 31.0% vs. 15.4% for FPG and 28.9% vs. 15.1% for 2 h PG, respectively. Genetic factors explained 43% and 41% of the variance of FPG, and 72% and 47% for impaired fasting glucose for males and females, respectively; environmental factors substantially contribute to 2hPG status and impaired glucose tolerance. In conclusion, in this cohort of healthy rural Chinese children and adolescents, we demonstrated that both FPG and 2hPG tracked well and was a strong predictor of prediabetes. The high proportion of children with top tertile of blood glucose progressed to prediabetes, and the incidence of prediabetes has a male predominance. Genetic factors play more important role in fasting than postload status, most of which was explained by unique environmental factors

Long-term follow-up and treatment in nine boys with X-linked creatine transporter defect

The creatine transporter (CRTR) defect is a recently discovered cause of X-linked intellectual disability for which treatment options have been explored. Creatine monotherapy has not proved effective, and the effect of treatment with L-arginine is still controversial. Nine boys between 8 months and 10 years old with molecularly confirmed CRTR defect were followed with repeated 1H-MRS and neuropsychological assessments during 4–6 years of combination treatment with creatine monohydrate, L-arginine, and glycine. Treatment did not lead to a significant increase in cerebral creatine content as observed with H1-MRS. After an initial improvement in locomotor and personal-social IQ subscales, no lasting clinical improvement was recorded. Additionally, we noticed an age-related decline in IQ subscales in boys affected with the CRTR defect

A twin study of chronic widespread pain.

A twin study of chronic widespread pain

Abstract P379: Adiposity Tracking and Its Heritability: A Longitudinal Study of Rural Chinese Children and Adolescents

Objectives: Examine adiposity tracking and estimate its heritability in a large prospective cohort of pre-pubertal and pubertal rural Chinese children. Methods: This report included 1317 children and adolescents from the Anqing region of China, aged 6 to 18 years at baseline, who also completed follow-up visit 6 years later. Anthropometric measures included body mass index (BMI), waist circumference (WC), total body fat (TBF), percent body fat (%BF), trunk fat (TRF), and percent trunk fat (%TRF). Adiposity measures were obtained by dual-energy X-ray absorptiometry (DEXA). Locally weighted nonparametric smoothing function (SAS LOESS, SAS Institute, Cary, NC, USA) were used to describe (1) “tracking” of adiposity measurements from baseline to 6-year follow-up, and (2) gender differences in the growth of adiposity measurements across age. Structural equation modeling was used to estimate the heritability of tracking using the software Mx. Results: All anthropometric measures, except for %TRF, tracked significantly from baseline to follow-up in both genders. The middle baseline tertile, in general, had the lowest degree of tracking. Subjects in a high baseline tertile for BMI, TBF, %TBF, WC, and TRF were significantly more likely to be in the high tertile of TBF, %TBF, TRF at the follow-up. There was no good predictor for %TRF. Gender and pubertal status did not affect tracking, for TBF in females, and WC in the older age-group. The genetic correlation of BMI=0.60 (0.46-0.72); TBF=0.43 (0.29-0.55); %TBF=0.37 (0.23-0.50); WC=0.35 (0.11-0.56); TR=0.41 (0.27-0.54); and %TR=0.33 (0.07-0.59). Conclusion: The strong tracking of adiposity measures in this pediatric population underscores the importance of closely monitoring individuals with high BMI or adiposity over time; those in the medium tertile should also be monitored for upward trend due to their “mobility”. Only BMI showed a strong genetic correlation between baseline and followup, suggesting that environmental changes can influence adiposity depots. Our data raises the possibility that individuals at risk of adult obesity can be identified at early age so that early intervention can be initiated to prevent or mitigate obesity and related complications. </jats:p