Serum leptin concentration poorly reflects growth and energy and nutrient intake in young children

Similar effects of milk protein and blends of milk and plant-based protein on appetite-related hormones in 7- to 8-year-old healthy Danish children: secondary analyses from the PROGRO randomised trial

AIM

The effect of different protein sources on the appetite-related hormones in children is largely unknown. We investigated the effect of milk protein versus blends of milk and rapeseed protein on plasma leptin and adiponectin in children.

METHODS

We included 88 Danish 7- to 8-year-old children randomised to receive 35 g protein/day for 4 weeks in 2018 as either milk protein or blends of milk and rapeseed protein (ratio 54:46 or 30:70). Outcomes included absolute and fat mass-adjusted adiponectin and leptin measured at baseline, Weeks 1 and 4.

RESULTS

There was no difference in changes in absolute and fat mass-adjusted adiponectin and leptin after 1 or 4 weeks between the three groups (p ≥ 0.100). Leptin increased within all groups (p ≤ 0.046). Combining the three groups, leptin and fat mass-adjusted leptin increased by 23% (95% CI 11;35) and 17% (6.4;29) during the intervention respectively (both p ≤ 0.001). Adiponectin variables did not change during the intervention period.

CONCLUSION

There were no differences between milk protein and blends of milk and rapeseed protein on absolute and fat mass-adjusted leptin and adiponectin in healthy children with a habitual intake of milk. However, leptin increased within all three groups. Future studies should further investigate effect on appetite-related hormones of rapeseed protein alone.

Metabolic Setup and Risks in Obese Children

BACKGROUND

In the past decades, the obesity epidemic in children of all ages has been an important research field for detecting the metabolic causes and consequences of obesity, the major focus being on insulin and adipocytokine levels. Metabolic work-up in obese children is recommended in the age group as young as 2-6 years. There is evidence that birth weight can be a factor causing obesity later in life accompanied by metabolic complications.

METHODS

Insulin, leptin, and adiponectin levels were analyzed in 269 obese children and 60 controls, as well as 110 newborn children with different birth weight and different length of gestation, using standard methods.

RESULTS

In 53.6% of the obese children, complications of obesity such as diabetes mellitus, obesity, hyperlipidemia, heart attack or stroke were found in family members. The peak insulinemia on OGTT was significantly higher in the pubertal compared to the prepubertal group (110.5± 75.9 μU/mL versus 72.2±62.7 μU/mL) (p<0.005). Glucose intolerance was confirmed in 24%. The leptin level was significantly higher and the adiponectin level was lower in pubertal obese children compared to the prepubertal children and controls (p<0.05). In newborns the leptin and adiponectin levels were in correlation with anthropometric parameters: body weight (BW), body length (BL), BW/BL, BMI, and the pondered index (p<0.05).

CONCLUSION

Obese children have high insulinemia in all ages, reaching its peak towards puberty. The leptin and adiponectin levels might be indicators of the metabolic syndrome. Our findings in newborns might influence the nutritional approach in the future in order to prevent complications of obesity.

Sociocultural characteristics, obesity and inflammatory biomarkers in Puerto Rican toddlers born in New York City

BACKGROUND

In the USA, Puerto Rican children have a higher prevalence of asthma than other Latino ethnicities, and acculturation is one of hypothesized reasons for this difference. We examined associations between sociocultural characteristics and serum leptin, high-sensitivity C-reactive protein (hsCRP), and body mass index (BMI), and further, among hsCRP, leptin levels, BMI percentiles, and allergic sensitization in 2-year-old children.

METHODS

IgE antibodies, leptin, and hsCRP concentrations were measured in serum from Puerto Rican toddlers (n = 143) born in New York City with a maternal history of allergy and/or asthma. Demographic and home characteristics questionnaires were administered to the mother, postpartum and two years later. Children's weight and height were measured to determine BMI percentiles.

RESULTS

More girls (60%) had leptin levels above the median compared with boys (37%) (p = 0.0063). Leptin was positively correlated with BMI (r = 0.25; p = 0.0042). Children in daycare were more likely to be obese (40% vs. 24% p < 0.06). Maternal birthplace was significantly associated with children's leptin but not with hsCRP. Leptin levels were lower for children whose mothers were born on the US mainland (GM = 2.5 ng/ml, 95% CI [2.2-2.7]) compared with those whose mothers were born in Puerto Rico or another country (GM = 3.2 ng/ml, 95% CI [2.2-3.9], t-test p = 0.01). Mothers born in another country were more likely than those born in the US mainland or Puerto Rico to have obese children (60% vs. 26% p < 0.02). Leptin, hsCRP, and BMI percentile were not associated with sensitization to any of the measured inhalant allergens or total IgE.

CONCLUSION

Even at a very young age, some acculturation factors were associated with biomarkers and anthropometric measures of obesity among this Puerto Rican pediatric population. To our knowledge, this is the first study demonstrating the association of mother's birth place with child BMI and leptin as early as 24 months.

Dietary determinants of subclinical inflammation, dyslipidemia and components of the metabolic syndrome in overweight children: a review

OBJECTIVE

To review and summarize the dietary determinants of the metabolic syndrome, subclinical inflammation and dyslipidemia in overweight children.

DESIGN

Review of the current literature, focusing on pediatric studies.

PARTICIPANTS

Normal weight, overweight, or obese children and adolescents.

RESULTS

There is a growing literature on the metabolic effects of excess body fat during childhood. However, few pediatric studies have examined the dietary determinants of obesity-related metabolic disturbances. From the available data, it appears that dietary factors are not only important environmental determinants of adiposity, but also may affect components of the metabolic syndrome and modulate the actions of adipokines. Dietary total fat and saturated fat are associated with insulin resistance and high blood pressure, as well as obesity-related inflammation. In contrast to studies in adults, resistin and adiponectin do not appear to be closely linked to insulin resistance or dyslipidemia in childhood. However, circulating leptin and retinol-binding protein (RBP) 4 correlate well with obesity, central obesity and the metabolic syndrome in children. Intakes of antioxidant vitamins tend to be low in obese children and may be predictors of subclinical inflammation. Higher fructose intake from sweets and sweetened drinks in overweight children has been linked to decreased low-density lipoprotein (LDL) particle size.

CONCLUSIONS

Dietary interventions aimed at reducing intakes of total fat, saturated fat and free fructose, whereas increasing antioxidant vitamin intake may be beneficial in overweight children. More research on the relationships between dietary factors and the metabolic changes of pediatric obesity may help to identify the dietary changes to reduce health risks.

Dietary sucrose intake is related to serum leptin concentration in overweight pregnant women

BACKGROUND

Overweight, characterized by low-degree systemic inflammation, predisposes women to impaired glucose metabolism during pregnancy. Adipokine leptin participates in the regulation of energy balance and immune action.

AIMS OF THE STUDY

Objective of the study was to evaluate if aberrations in glucose metabolism during pregnancy are related to leptin concentration and whether serum leptin concentration is affected by diet composition.

SUBJECTS AND METHODS

Normal-weight (n = 61) and overweight or obese (BMI > 25, n = 42) pregnant women visited study clinic at third trimester of pregnancy and one month postpartum. Serum fasting leptin and insulin as well as plasma glucose concentrations were measured, insulin resistance (HOMA) and sensitivity (QUICKI) calculated, and dietary intake from food records determined.

RESULTS

In overweight women leptin concentration was significantly higher both in pregnancy, 45.27 (95% CI 39.40-51.14) ng/ml, and postpartum, 31.84 (27.38-36.30) ng/ml, than in normal-weight women, 31.09 (95% CI 27.80-34.37) ng/ml and 16.23 (13.93-18.53) ng/ml, respectively. Equally, blood glucose concentration during pregnancy was higher, 4.82 (4.67-4.97)mmol/l, and insulin concentration, 15.34 (12.00-18.68) mU/l, more pronounced in overweight compared to normal-weight women, 4.51 (4.42-4.61) mmol/l and 8.28 (7.21-9.36) mU/l, respectively. Significantly higher HOMA and lower QUICKI were also detected in overweight compared to normal-weight women. At third trimester of pregnancy, leptin concentration correlated positively with insulin concentration in normal-weight (r = 0.561, P = 0.002) and overweight women (r = 0.736, P < 0.001), as well as with HOMA (r = 0.568, P = 0.002 and r = 0.731, P < 0.001, respectively) whereas negative association was found with QUICKI in normal-weight (r = -0.484, P = 0.011) and overweight women (r = -0.711, P < 0.001). Importantly, serum leptin concentration was affected by dietary sucrose intake both as quantitatively (r = 0.424, P = 0.009) and relative to energy intake (r = 0.408, P = 0.012) in overweight but not in normal-weight pregnant women.

CONCLUSIONS

Overweight-related elevation in serum leptin is associated with impaired regulation of glucose metabolism during pregnancy. The novel finding that dietary sucrose intake is related to serum leptin concentration is in line with the current dietary recommendations to overweight pregnant women with impaired glucose metabolism advising the lower intake of sucrose during pregnancy.

Effect of Genistein with Carnitine Administration on Lipid Parameters and Obesity in C57Bl/6J Mice Fed a High-Fat Diet

Soy products are mainly composed of proteins, phytochemicals such as isoflavones, soy lipids, and carbohydrates. It is unclear whether an individual component alone or a combined effect of multiple bioactive compounds contributes to the beneficial properties of soy. We investigated the effect of dietary genistein (the principal soy isoflavone) alone and combined with L-carnitine to evaluate possible synergistic effects on the intentionally induced prediabetic state characterized by insulin resistance and obesity in C57Bl/6J mice fed a high-fat diet (HD). In the HD-alone group, abdominal and back fat relative to total body weight were significantly higher compared with other groups including those fed normal diet (ND). Among the HD groups, final weight gains of the HD plus genistein (HD+G) and HD plus genistein plus L-carnitine (HD+G+C) groups were lower compared with that of the control (HD-alone). Especially in liver, the results showed that genistein with carnitine transcriptionally up-regulated expressions of acyl-coenzyme A synthetase (ACS) and carnitine palmitoyltransferase-I (CPT-I) by approximately 50% and 40%, respectively, compared with genistein alone. However, the up-regulation of CPT-I did not directly reflect the enzyme activity of CPT-I. On the other hand, the effects of genistein and genistein with carnitine on the expressions of ACS and CPT-I in muscle were not significant. Our study suggests that genistein with carnitine exerts anti-obesity effects, probably by modulating peroxisome proliferator-activated receptor-associated genes. However, further work is needed to elucidate the possible mechanisms by which genistein and carnitine intervene.