Resistance to the antilipolytic effect of insulin in adipocytes of African-American compared to Caucasian postmenopausal women

High fatty acid (FA) flux is associated with systemic insulin resistance, and African-American (AA) women tend to be more insulin resistant. We assessed possible depot and race difference in the antilipolytic effect of insulin in adipocytes isolated from abdominal (Abd) and gluteal (Glt) subcutaneous (sc) adipose tissue of overweight, postmenopausal AA and Caucasian (C) women. Percent body fat, fasting insulin, visceral adiposity, and adipocyte size was higher in AA women. Disinhibited lipolysis (presence of adenosine deaminase) per unit adipocyte surface area was similar in Abd and Glt and in AA and C. However, rates of ‘basal’ [submaximal phenylisopropyl adenosine (PIA)-suppressed] and insulin-suppressed lipolysis were higher in Abd of AA compared with C women even after adjustment for percent fat and visceral fat area. The race difference in rates of PIA- and insulin-suppressed lipolysis in AA were correlated with their hyperinsulinemia, but AA race, independent of fasting insulin, was associated with lower responsiveness (percent suppression) to submaximal insulin concentrations, although sensitivity (ED50) was not affected. Overall, these data are consistent with the hypothesis that decreased responsiveness of Abd adipocytes to antilipolytic effectors may contribute to higher FA availability and thereby to racial differences in insulin resistance

Ethnic differences in the relationship between fasting leptin and BMI in children

OBJECTIVE: To compare the relationship between fasting serum leptin levels and body mass index (BMI) in children from different ethnic groups. SUBJECTS: Children aged 6 - 10 y from rural Gambia (n = 471) and central Italy ( n = 839). MEASUREMENTS: Anthropometry ( z- score of BMI) and fasting serum leptin concentrations. RESULTS: The Italian children had significantly higher mean BMI z- scores than the Gambian children ( males: Italy 1.58, Gambia - 1.44, Pless than or equal to0.0001; females: Italy 1.33, Gambia - 1.42, Pless than or equal to0.0001) and significantly higher serum leptin concentrations ( males: Italy 8.86 ng ml(-1), Gambia 1.78 ng ml(-1), Pless than or equal to0.0001; females: Italy 11.31 ng ml(-1), Gambia 2.22 ng ml(-1), Pless than or equal to0.0001). A significantly different relationship was observed between z- score of BMI and serum leptin levels in the Gambian and the Italian children for both boys and girls. CONCLUSION: A different relationship exists between z- score of BMI and leptin levels in these two groups of children from very diverse ethnic backgrounds. Future studies using detailed measures of body composition and energy balance are needed to help understand this relationship

Efficacy and Safety of a Tight Glucose Control Protocol in Critically Ill Term Neonates

Background: A large single-center randomized trial showed that treating hyperglycemia in critically ill children improved outcome, despite an increased incidence of hypoglycemia, especially in infants. Objectives: We evaluated the efficacy and incidence of hypoglycemia using a tight glucose protocol in critically ill term neonates. Methods: Term hyperglycemic (>8 mmol·l -1; >144 mg·dl -1) neonates treated with a tight glucose protocol during a 3.5-year period