Elevated remnant lipoproteins may increase subclinical CVD risk in pre-pubertal children with obesity: a case-control study.

OBJECTIVES: Current clinical guidelines to assess paediatric cardiovascular disease (CVD) risk heavily rely on cholesterol parameters that are generally normal for obese children. Remnant lipoproteins have emerged as a critical CVD risk factor particularly in adults with normolipidemia. We assessed remnant lipoprotein concentration (measured by apolipoprotein [apo] B48) and its relationship with other traditional CVD risk biomarkers in pre-pubertal children with obesity. METHODS: Pre-pubertal children (n = 78) with obesity (n = 39, 9.9 ± 0.3 years old) as well as sex-matched normal-weight controls (n = 39, 9.8 ± 0.3 years) were assessed for anthropometry, blood pressure and fasting plasma biochemical parameters for remnant lipoprotein, lipid and glucose/insulin metabolism, and inflammatory status. RESULTS: Children with obesity had striking 2-fold higher apoB48-containing remnant lipoproteins concentrations relative to normal-weight peers; the magnitude of elevation in the remnant lipoproteins is comparable to the levels previously reported for adults with established CVD and type-2 diabetes. Fasting apoB48 was positively correlated with fasting triglyceride concentration in children with obesity (r = 0.51, P < 0.001) and their normal-weight peers (r = 0.45, P < 0.01). Traditional CVD biomarkers including low-density lipoprotein cholesterol showed no difference between groups and remained within the normal range for a paediatric population. CONCLUSION: Elevated apoB48-containing remnant lipoprotein is a stronger biomarker for paediatric CVD risk compared to traditional cholesterol parameters and may be associated with early adaptation of the intestine during obesity. Further investigation of abnormalities associated with the secretion and/or clearance of atherogenic remnant lipoproteins during the postprandial state may yield insight into our understanding of and therapeutic targets for managing risk for CVD in children with obesity.

Variation in temperature increases the cost of living in birds.

The effect of temperature variability on laying birds was studied experimentally, using Japanese quail. Two aspects of temperature variability were investigated: the effects of regular daily variation in temperature, and of a sudden change in temperature. Both of these may become more common as a consequence of climate change. These manipulations were carried out at two levels of food supply. Energy expenditure increased with higher daily temperature variation, and also after a sudden change in temperature, taking several days to settle to a constant level. Manipulating daily temperature variation also resulted in smaller eggs being laid under more variable temperatures, when food quality was also low. The results demonstrate that day-to-day variation in temperature, as well as mean temperature, affects energy expenditure, which can have consequences for egg production.