PPARGC1A DNA methylation in subcutaneous adipose tissue in low birth weight subjects--impact of 5 days of high-fat overfeeding

OBJECTIVE

Increased DNA methylation of the metabolic regulator peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PPARGC1A) has been reported in skeletal muscle from type 2 diabetes (T2D) subjects and from low birth weight (LBW) subjects with an increased risk of T2D. High-fat overfeeding increases PPARGC1A DNA methylation in muscle in a birth weight dependent manner. However, PPARGC1A DNA methylation in subcutaneous adipose tissue (SAT) in LBW subjects has not previously been investigated. Our objective was to determine PPARGC1A DNA methylation and mRNA expression in basal and insulin-stimulated SAT from LBW and matched normal birth weight (NBW) subjects during control and high-fat overfeeding.

MATERIALS/METHODS

Nineteen young healthy men with LBW and 26 NBW controls were studied after both a 5-day high-fat overfeeding and a control diet in a randomized crossover setting. DNA methylation was assessed with bisulfite sequencing and mRNA expression with quantitative real-time PCR.

RESULTS

Following high-fat overfeeding, increased SAT PPARGC1A DNA methylation was observed in LBW subjects but not in NBW controls. Basal SAT PPARGC1A mRNA expression was unaffected by diet and similar in the two groups. However, LBW subjects showed an increased SAT PPARGC1A mRNA expression during insulin-stimulation. SAT PPARGC1A methylation correlated inversely with mRNA expression during insulin-stimulation.

CONCLUSIONS

The study adds to the increasing awareness of PPARGC1A DNA methylation being flexible and influenced by high-fat overfeeding in a birth weight dependent manner with muscle and fat responding differently. Further data are needed to understand the role of PPARGC1A DNA methylation in insulin resistance and developmental programming of T2D.

Quality of life at age 18 years after extremely preterm birth in the post-surfactant era

OBJECTIVES

To assess the self-reported quality of life, health status, self-esteem, and functional outcomes at age 18 years of extremely preterm (EP; <28 weeks gestation) or extremely low birth weight (ELBW; birth weight <1000 g) adolescents born in 1991-1992 compared with normal birth weight (birth weight >2499 g) controls, and, within the EP/ELBW cohort, to assess whether these outcomes are related to gestational age or birth weight.

STUDY DESIGN

Self-reported measures of quality of life, health status, self-esteem, and functional outcomes were obtained at age 18 years from a geographic cohort of all survivors born EP/ELBW in 1991-1992 in the state of Victoria, Australia, along with matched normal birth weight controls.

RESULTS

Data were available from 194 EP/ELBW and 148 control adolescents. EP/ELBW adolescents reported similar overall quality of life, health status, and self-esteem as controls (P > .05). Birth at younger gestational age or lower birth weight were not related to poorer quality of life within the EP/ELBW cohort (P > .05). EP/ELBW adolescents reported less physical activity (OR, 0.5; 95% CI, 0.3-0.8; P < .01), sexual activity (OR, 0.6; 95% CI, 0.4-0.9; P = .01), and alcohol intake (OR, 0.5; 95% CI, 0.3-0.8; P = .01) compared with controls. Other aspects of risk-taking behavior were similar in the 2 groups (P > .05).

CONCLUSION

EP/ELBW individuals born after the introduction of exogenous surfactant are transitioning well into young adulthood, despite the fact that more of the tiniest and most immature infants survive than ever before. They report similar quality of life, self-esteem, and social and risk-taking behaviors as controls.