Calorically restricted diets decrease PCSK9 in overweight adolescents.

BACKGROUND AND AIMS: Nutritional therapy is the first line approach to treatment of hyperlipidemia in childhood. Proprotein convertase subtilisin kexin type 9 (PCSK9) is a key regulator of plasma cholesterol levels and a target of novel lipid-lowering pharmacotherapies. We examined the effects of an intensive nutritional intervention on PCSK9 levels in overweight adolescents with cardiovascular disease (CVD) risk factors. METHODS AND RESULTS: Twenty seven obese and overweight adolescents with CVD risk factors were assigned to either a low fat or low glycemic load diet. During an 8-week "Intensive Phase," assigned meals were delivered to the home, and all participants received weekly in-person home nutrition counseling and phone calls. The subjects then underwent a 4-month "Maintenance Phase" without food provision and with no in-person contact. Anthropometric measurements, laboratory data, and serum PCSK9 protein levels were measured at baseline, 8 weeks, and 6 months. PCSK9 decreased by 16.5% at 8 weeks (201.2 ± 56.3 vs 165.6 ± 58.4 ng/mL; p < 0.001); PCSK9 levels returned to baseline levels at 6 months, after the Maintenance Phase. Change in PCSK9 was associated with change in fasting insulin, HOMA-IR, and AUC insulin, independent of weight loss. CONCLUSIONS: PCSK9 decreased in youth participating in an intensive dietary intervention. Change in HOMA-IR was associated with change in PCSK9, independent of weight loss, suggesting an important relationship with insulin sensitivity. ClinicalTrials.gov Identifier: NCT01080339.

Helpful or harmful? Prospective association between weight misperception and weight gain among overweight and obese adolescents and young adults.

BACKGROUND/OBJECTIVE: Weight misperception is common among adolescents with obesity, but it is not known whether weight perception is related to future weight gain. The objective of the study was to examine the prospective association between accurate weight perception versus weight misperception and weight change among youth who are overweight or obese. SUBJECTS/METHODS: Using a subsample of The National Longitudinal Study of Adolescent to Adult Health Wave II cohort, we used linear regression modeling (adjusted for age, baseline body mass index (BMI), parental education, household percent federal poverty level, depression, race and ethnicity) to examine the prospective association between weight misperception (that is, perceiving oneself to be under or normal weight) among 2738 overweight and obese youth and subsequent BMI change from Wave II (1996) to Wave IV (2008-2009). Mean age at baseline (Wave II) was 15.9 (0.1). RESULTS: Fifty-seven percent of males and 80% of females accurately perceived themselves as overweight. In fully adjusted models, weight misperception was associated with less BMI gain among youth who were overweight and obese. Specifically, youth who perceived themselves to be at a healthy weight had lower BMI gains (males: ß= -1.43, 95% confidence interval (CI)=(-2.26, -0.60), P=0.001; females: ß= -1.35, 95% CI=(-2.59, -0.11), P=0.035) from Wave II to IV relative to those who accurately perceived themselves as overweight or obese. CONCLUSIONS: Contrary to commonly held assumptions, weight misperception among a non-clinical sample of youth who were overweight or obese predicted lower future weight gain. Efficacy of efforts to correct weight misperception should be rigorously examined to assess for both intended and unintended consequences.

Racial/ethnic differences in accuracy of body mass index reporting in a diverse cohort of young adults.

Surveillance data describing the weight status of the U.S. population often rely on self-reported height and weight, despite likely differences in reporting accuracy by demographics. Our objective was to determine if there were racial/ethnic differences in accuracy of self-reported body mass index (BMI) in a diverse nationally representative sample of young people. Using data from Wave III (data collected in 2001-2002) of the National Longitudinal Study of Adolescent Health when respondents were aged 18-26, we used gender-stratified multivariable linear regression models to examine the association of race/ethnicity and self-reported BMI controlling for measured BMI while also adjusting for factors known to be associated with weight self-perception. Black males and females (b(Female)=0.45, confidence interval (CI): 0.19, 0.71; b(Male)=0.34, CI: 0.17, 0.51) and Hispanic females (b(Female)=0.30, CI: 0.08, 0.52) and Native American males (b(Native) American=0.87, CI: 0.15, 1.58) reported higher BMIs than their similarly weighted White peers, leading to more accurate BMI reporting in these groups at higher BMIs. Caution should be taken in interpreting results from studies relying on self-reported BMI, as they may exaggerate racial/ethnic differences in weight status.