Ambulatory Blood Pressure Monitoring in Lean, Obese and Diabetic Children and Adolescents.

AIM: To determine if children and adolescents who have obesity (Ob) or type 2 diabetes (T2DM) of relatively short duration have impaired cardiovascular function compared with lean subjects using 24-hour ambulatory blood pressure as a surrogate measure of evaluation. METHODS: We enrolled 100 African-Caribbean subjects (45 males/55 females), mean ages 14.4-15.2 years (range 11.8-18.5 years) and Tanner stage 4.2-4.8. Mean BMI for the Ob (n = 40), T2DM (n = 39) and lean (n = 21) groups were 40.3, 34.2 and 20.8, respectively (p < 0.01, Ob and T2DM vs. lean). Mean hemoglobin A1c in lean and Ob was 5.4 and 5.5% compared to 8.8% in T2DM (p < 0.001, T2DM vs. lean and Ob). Ambulatory blood pressure was recorded every 20 min over 24 h using Spacelabs 70207. RESULTS: Mean 24-hour, daytime and nighttime systolic blood pressure was significantly higher in Ob and T2DM compared with lean subjects (mean 24-hour 117 and 120 vs. 109 mm Hg; daytime 121 and 123 vs. 113 mm Hg; and nighttime 109 and 115 vs. 101 mm Hg; p < 0.01 for all time periods). The nocturnal systolic dip in Ob and T2DM did not differ from that of lean, whereas nocturnal diastolic dip decreased significantly in Ob and T2DM compared to lean (11.5 and 10.4 vs. 20.6 mm Hg; p < 0.01). Mean pulse pressure was significantly increased in the Ob and T2DM groups compared to lean subjects (51 and 54 vs. 45 mm Hg; p < 0.01). CONCLUSION: Adolescent Ob and T2DM groups share adverse risk factors, which may be harbingers of adult cardiovascular events.

Vascular compliance in lean, obese, and diabetic children and adolescents: a cross-sectional study in a minority population.

BACKGROUND: In adults, both obesity and type 2 diabetes mellitus (T2DM) are positively correlated with cardiovascular disease mortality and arterial stiffness. Several studies of adults have shown that both obesity and T2DM are independently associated with increased arterial stiffness. However, little is known about the relationship between arterial compliance and cardiovascular disease risk in children. We assessed whether large and small arterial compliance is impaired in obese and diabetic pubertal children. METHODS: One hundred children of African-Caribbean ethnicity, aged 14-16 years, including 21 lean children (between the 25th and 75th percentile), 40 obese children (>95th percentile), and 39 children with T2DM diagnosed by American Diabetes Association criteria were studied. Arterial compliance of the large (C1) and small (C2) vessels was measured using radial arterial diastolic pulse wave contour analysis. RESULTS: C1 did not differ significantly between lean, obese, and T2DM subjects. C2 was significantly greater in obese and T2DM subjects (10.9 ± 1 and 10.4 ± 0.7 ml/mm Hg × 100 ml, respectively) compared to lean subjects (7.8 ± 0.8 ml/mm Hg × 100 ml; p < 0.05). C2 was also significantly greater in T2DM subjects receiving antihypertensive drug therapy than in diabetic subjects not on antihypertensive treatment. CONCLUSION: Increased compliance in diabetic and obese children compared to lean subjects could be secondary to premature maturation of the vascular system; whether this early maturation can translate into a subsequent rise in the incidence of cardiovascular events related to diabetes and obesity can only be determined by long-term follow-up of these patients.

Continuous monitoring of blood pressure in children and adolescents,a review of the literature.

Continuous or ambulatory blood pressure monitoring (CBPM or ABPM) is becoming a useful tool in the early detection of hypertension in children and adolescents. With increased obesity in pediatrics, chronic diseases such as hypertension, diabetes, dyslipidemia and metabolic syndrome which was more commonly seen in adults in the early years, can now be seen in this population. This review provides the clinical reports of the use of CBPM for diagnosis and management of hypertension in the pediatric population.

Estimates of body fat in children by Hologic QDR-2000 and QDR-4500A dual-energy X-ray absorptiometers compared with deuterium dilution.

We evaluated the accuracy with which the Hologic QDR-4500A and QDR-2000 densitometers measure fat mass (FM) in 95 children. FM was derived from total body water measured by deuterium dilution (DD) in all children, by QDR-4500A in 50, and by QDR-2000 in 45 children. Compared with DD, both instruments underestimated FM (QDR-4500A: 3.35 +/- 2.5 kg, P < 0.0001; QDR-2000: 1.05 +/- 1.5 kg, P < 0.0001). Both absorptiometers showed magnitude biases relative to DD (QDR-4500: r = +0.70, P < 0.001; QDR-2000: r = -0.51, P < 0.001). We conclude that neither densitometer is equivalent to DD for estimation of children's FM. The QDR-4500A's current calibration seems to provide an even greater underestimate of FM than the QDR-2000.

Pancreatic beta-cell hyperactivity in morbidly obese adolescents.

beta-cell hyperactivity, with increased beta-cell mass in the pancreas, contributes to insulin oversecretion in response to insulin resistance. beta-cell mass expansion, also known as "endocrine pancreas plasticity", is an adaptation to variations in insulin demand, is generally observed in obese persons and in women during late pregnancy. In obese persons, increased free fatty acids contribute to beta-cell growth. It is believed that type 2 diabetes develops in those persons unable to respond to an increased insulin demand with a high rate of beta-cell proliferation. Impairment of insulin secretion may originate from a genetic predisposition as well as aggravated by high lipid and glucose levels. Better understanding of endocrine pancreas plasticity and its regeneration mechanisms could lead to new treatment modalities for type 2 diabetes. Review of literature of pancreatic beta-cell hyperactivity in obesity and its existence in morbidly obese adolescents is hereby presented.

The prevalence of metabolic syndrome in inner city obese African-American youth.

BACKGROUND: In children and adolescents, obesity increases the risk of metabolic syndrome (MS). OBJECTIVE: We examined the prevalence of MS among obese and morbidly obese children and adolescents referred to an obesity clinic in a university-based hospital center. DESIGN/METHODS: A total of 194 obese (BMI > 95%) children and adolescents were evaluated. Fasting glucose, insulin, lipid panel, BMI, blood pressures were obtained. Main outcome measures were prevalence of components of MS by modified National Cholesterol Education Program (NCEP or Adult Treatment Panel 111 (ATP 111), with MS defined as > or = 3 components. RESULTS: There were 113 females (58%) and 81 males (42%); mean age of the cohort was 11.9 years (range: 3.4-18.8 years). One hundred seventy four (90%) of the cohort were African-American, 14 (7%) were Hispanic and 6 (3%) were others. Mean BMI z- score was 2.5 and ranged from 1.7 to 4.8. Thirty five percent of the total cohort had MS. Among the morbidly obese patients (BMI z-score > 2.5), the prevalence of the MS increased to 44%. Impaired fasting glucose (5.8 %), impaired glucose tolerance (6.5%) and silent diabetes mellitus (2.4%) were also identified. CONCLUSIONS: One third of obese patients referred to a hospital-based obesity center had the MS and nearly half of morbidly obese children and adolescents had MS.