Lipid Profiles, Inflammatory Markers, and Insulin Therapy in Youth with Type 2 Diabetes

OBJECTIVES

Data regarding atherogenic dyslipidemia and the inflammation profile in youth with type 2 diabetes is limited and the effect of insulin therapy on these variables has not previously been studied in youth. We determined the impact of insulin therapy on lipid and inflammatory markers in youth with poorly controlled type 2 diabetes.

STUDY DESIGN

In the Treatment Options for type 2 Diabetes in Adolescents and Youth (TODAY) multicenter trial, 285 participants failed to sustain glycemic control on randomized treatment (primary outcome, glycated hemoglobin A1c [HbA1c] at ≥8% for 6 months); 363 maintained glycemic control (never reached primary outcome). Statins were used for a low-density lipoprotein cholesterol of ≥130 mg/dL. Upon reaching the primary outcome, insulin was started. Changes in lipids and inflammatory markers (slopes over time) were examined.

RESULTS

Progression of dyslipidemia was related to glycemic control. In those with the primary outcome, insulin therapy impacted HbA1c modestly, and dampened the increase in total cholesterol, low-density lipoprotein cholesterol, and total apolipoprotein B, although statin use increased from 8.6% to 22% year after the primary outcome. The increase in triglycerides and plasma nonesterified fatty acids stabilized after insulin was started, independent of HbA1c. There was an increase in high-sensitivity C-reactive protein that continued after insulin initiation, related to HbA1c and percent overweight.

CONCLUSIONS

Worsening dyslipidemia and inflammation over time raise concern regarding premature development of atherosclerosis in youth with type 2 diabetes. Insulin therapy has a limited benefit in the absence of glycemic control. Strategies to achieve better glycemic control are needed.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00081328.

Impact of lifestyle behavior change on glycemic control in youth with type 2 diabetes

BACKGROUND

Little is known about the feasibility and impact of lifestyle intervention, determined by change in diet and cardiovascular fitness (CRF), on glycemic control in youth who are overweight with type 2 diabetes. This was examined in the Treatment Options for type 2 Diabetes in Adolescents and Youth (TODAY) clinical trial cohort from across 15 US centers.

SUBJECTS

TODAY enrolled 699 youth aged 10 to 17 years with type 2 diabetes <2 years and body mass index ≥85th percentile at baseline.

METHODS

Dietary data were collected by an interviewer-administered food frequency questionnaire; CRF was assessed using a submaximal cycle ergometer test. Change from baseline in these variables was analyzed using generalized linear mixed models for both continuous and categorical measures. Models were adjusted for age, baseline HbA1c, treatment group, and medication adherence. Data were collected at baseline, 6, and 24 months. Trial registration ClinicalTrials.gov NCT00081328.

RESULTS

At 6 months, ~25% of females and ~33% of males improved CRF. In males, this was related to a decreased HbA1c (P = .001) and a lower percent experiencing glycemic failure (HbA1c ≥8%; P = .007). Females who decreased their saturated fat intake and/or increased their fiber intake had lower HbA1c at month 24 (P = .01 and P = .007, respectively). Males who increased their sweetened beverage intake at 6-month follow-up were at a 1.6-fold higher risk of experiencing glycemic failure (P = .04).

CONCLUSIONS

Few youth improved fitness and/or diet over time, although those who did showed a beneficial impact on glycemic outcomes. Although lifestyle behaviors are difficult to change in youth with type 2 diabetes, interventions are needed that are feasible (in scope, complexity, and demands), sustainable, and clinically meaningful.

Insulin-like growth factor-I and insulin-like growth factor binding protein-1 are related to cardiovascular disease biomarkers in obese adolescents

CONTEXT

Insulin-like growth factor (IGF)-I and IGF binding protein (IGFBP)-1 have been linked to cardiovascular disease (CVD) risk and pathophysiology in adults, but there are limited data in youth.

OBJECTIVE

The aim of the study was to examine the relationship between IGF and IGFBP-1 with traditional and non-traditional CVD risk factors including inflammatory markers and body composition in an obese pediatric cohort.

DESIGN

A cross-sectional study.

SETTING

The study was carried out at a university children's hospital.

SUBJECTS

Sixty-one obese non-diabetic adolescents.

OUTCOMES

Fasting IGF-I, IGFBP-1, lipoprotein profiles, high-sensitivity C-reactive protein (hsCRP), and total adiponectin as well as insulin sensitivity measures, blood pressure (BP), and anthropometrics.

RESULTS

IGFBP-1 was negatively associated with insulin sensitivity measures, body mass index (BMI), and diastolic BP in males. IGF-I was negatively associated with hsCRP (r = -0.479, p < 0.0005), and IGFBP-1 was positively associated with adiponectin (r = 0.545, p < 0.0005). The IGF-I/CRP and IGFBP-1/adiponectin associations remained significant when controlling for both BMI and insulin sensitivity index (SI ). Both IGF-I and IGFBP-1 were negatively associated with waist circumference (r = -0.327 and r = -0.275, respectively) and sagittal abdominal diameter (r = -0.333 and r = -0.371, respectively), while IGFBP-1 was negatively associated with fat mass (r = -0.347, p = 0.01) as well as neck circumference and fat-free mass in males. Controlling for BMI z-score and SI , IGFBP-1 remained negatively associated with diastolic blood pressure (r = 0.706, p = 0.001 and neck circumference (r = -0.548, p = 0.15) in males.

CONCLUSIONS

IGF-I and IGFBP-1 associate with CVD risk markers and may add to clinical assessments of cardiometabolic dysfunction in youth.

Interrelationships between obesity, obstructive sleep apnea syndrome and cardiovascular risk in obese adolescents

BACKGROUND/OBJECTIVES

Obstructive sleep apnea syndrome (OSAS) may be a cardiovascular disease (CVD) risk factor independently of obesity in adults. Pediatric studies have associated OSAS with endothelial dysfunction, but few studies have examined relationships between OSAS and macrovascular sequelae. Our objective was to examine OSAS's independent contribution to macrovascular CVD risk measures in obese adolescents.

SUBJECTS/METHODS

This cross-sectional observational study was conducted at Children's Hospital of Philadelphia Clinical Research and Academic Sleep Centers, and University of Pennsylvania Vascular Research Unit. Thirty-one obese non-diabetic adolescents underwent anthropometric measurements, overnight polysomnography, fasting laboratory draw and cardiovascular imaging. Cardiovascular outcome measures included maximal carotid intima-media thickness (cIMTmax), a measure of carotid structural changes, and carotid-femoral pulse wave velocity (CFPWV), an aortic stiffness measure whose relationship vis-à-vis OSAS in children has not been previously examined. Carotid diameter and augmentation index (AIx, measuring central pressure augmentation from wave reflections) were assessed. Potential confounding variables examined included blood pressure, lipoproteins, high-sensitivity C-reactive protein, insulin and glucose.

RESULTS

The apnea hypopnea index, a primary OSAS measure, was not associated with cIMTmax, carotid diameter, CFPWV or AIx. body mass index (BMI) associated positively with cIMTmax (r=0.52, P=0.006) and CFPWV (r=0.45, P=0.01). Mean asleep end-tidal CO2 was negatively associated with carotid diameter (r=-0.63, P<0.0005). Insulin levels were negatively associated with AIx (r=-0.53, P=0.02).

CONCLUSIONS

OSAS did not predict carotid structural changes or arterial stiffness independently of BMI in obese adolescents. Higher insulin levels associated with lower central pressure wave augmentation. Finally, long-term hypercapnia may predispose to carotid narrowing.

Longitudinal Correlates of Health Risk Behaviors in Children and Adolescents with Type 2 Diabetes

OBJECTIVES

To characterize, during a 2-year period, the proportion of youth with type 2 diabetes (T2D) enrolled in the Treatment Options for Type 2 Diabetes in Adolescents and Youth study that reported ever at least trying smoking cigarettes and/or drinking alcohol.

STUDY DESIGN

Longitudinal data were examined for participants with T2D ages 10-18 years at baseline. Youth psychosocial, parent/family, environmental, and biological correlates of trying health risk behaviors were tested via cross-sectional multivariate models at each time point. Longitudinal models were explored for selected factors.

RESULTS

Data were obtained from the Treatment Options for Type 2 Diabetes in Adolescents and Youth study's ethnically diverse participants at baseline (N=644), 6-month (N=616), and 24-month (N=543) assessments. The percentage of youth ever trying only smoking remained stable at 4%; only drinking alcohol increased from 17% to 26%, and both smoking and drinking increased from 10% to 18% during the 2-year period. Factors related to trying health risk behaviors were older age, male sex, non-Hispanic white race-ethnicity, lower grades, more depressive symptoms, and stressful life events. Depressive symptoms, stressful life events, and body mass index Z-score (the latter with smoking only) were related to engagement in health risk behaviors over time.

CONCLUSIONS

Youth with T2D who are already at risk for health complications and who reported engaging in activities that further increase the likelihood of life-threatening morbidities were characterized. Although most correlates of trying these risk behaviors are nonmodifiable, intervention efforts may need to focus on potentially modifiable factors, such as depressive symptoms and lower grades.

Anthropometric measures of abdominal adiposity for the identification of cardiometabolic risk factors in adolescents

Sagittal abdominal diameter (SAD) was obtained in 65 adolescents referred for assessment of cardiometabolic risk. We found that SAD was associated with cardiometabolic risk factors independent of BMI in males, but that SAD was not superior to BMI or other measures of abdominal adiposity for the detection of metabolic syndrome.

Population-based survey of the prevalence of type 1 and type 2 diabetes in school children in Philadelphia

BACKGROUND

Population-based (PB) registries of type 1 diabetes mellitus (T1DM) in children have been essential in determining the geographic, racial, and temporal patterns of the disease. There is a paucity of PB data on the prevalence of type 1 and type 2 diabetes (T2DM) in youth.

METHODS

The prevalence of diabetes in children was determined using a PB survey of the 628 schools in Philadelphia. Data obtained included type of diabetes, date of birth, race, gender, date of diagnosis, diabetes treatment, and most recent height and weight.

RESULTS

The survey was completed by nurses at 510 schools (81% of schools) representing 252,896 children (70% of children in Philadelphia). Prevalence (per 1000) was computed. The survey identified 492 cases (355 T1DM, 88 T2DM, 49 type unknown). The overall prevalence of T1DM was 1.58 (0.73 White, 0.56 African American, 0.50 Hispanic); of T2DM was 0.35 (0.03 White, 0.28 African American, 0.05 Hispanic). Mean age at diagnosis was 8.6 and 11.9 years for T1DM and T2DM, respectively. The prevalence of T1DM was higher in boys--T2DM was higher in girls. Of children with T2DM, 25% were treated with insulin. BMI was ≥95th percentile in 20% of children weighed (10% of T1DM, 57% of T2DM).

CONCLUSIONS

Although the Philadelphia Pediatric Diabetes Registry is the longest ongoing US registry of its kind, these are the first PB diabetes prevalence data of children in Philadelphia. PB studies in schools are able to capture children with diabetes who are diagnosed and treated in a variety of settings.

Threshold for improvement in insulin sensitivity with adolescent weight loss

OBJECTIVES

To assess the association of weight loss and insulin sensitivity, glucose tolerance, and metabolic syndrome (MS) in obese adolescents following weight loss treatment, and to determine the threshold amount of weight loss required to observe improvements in these measures.

STUDY DESIGN

A randomized, controlled behavioral weight loss trial was conducted with 113 obese adolescents. Changes in fasting insulin, homeostasis model assessment of insulin resistance, whole body insulin sensitivity index (WBISI), body mass index (BMI), and MS criteria were assessed at baseline and at month 4.

RESULTS

There was significant improvement in all measures of insulin sensitivity at month 4. Mean fasting insulin dropped from 22.3 to 16.6 μU/mL (P < .0001). Homeostasis model assessment of insulin resistance decreased significantly from 4.9 to 3.7 (P = .001) and WBISI increased significantly from 2.87 to 3.98 (P < .0001). An 8% reduction in BMI led to a significant improvement in WBISI (P = .03) and was the optimal threshold. Fewer individuals met criteria for MS after weight loss (P = .0038), although there were no significant changes in the individual features of the syndrome.

CONCLUSIONS

In this trial, weight loss at month 4 was associated with improved insulin sensitivity in obese adolescents. An approximate decrease in BMI of 8% was the threshold level at which insulin sensitivity improved. As more weight loss programs are designed for obese adolescents, it will be important to have reasonable weight loss goals that will yield improvements in metabolic and cardiovascular disease risk factors.

Increasing incidence of type 1 diabetes in youth: twenty years of the Philadelphia Pediatric Diabetes Registry

OBJECTIVE

The purpose of this study was to describe the incidence of type 1 diabetes in children in Philadelphia from 2000-2004, compare the epidemiology to the previous three cohorts in the Philadelphia Pediatric Diabetes Registry, and, for the first time, describe the incidence of type 2 diabetes.

RESEARCH DESIGN AND METHODS

Diabetes cases were obtained through a retrospective population-based registry. Hospital inpatient and outpatient records were reviewed for cases of type 1 and type 2 diabetes diagnosed from 1 January 2000 to 31 December 2004. The secondary source of validation was the School District of Philadelphia. Time series analysis was used to evaluate the changing pattern of incidence over the 20-year period.

RESULTS

The overall age-adjusted incidence rate in 2000-2004 of 17.0 per 100,000 per year was significantly higher than that of previous cohorts, with an average yearly increase of 1.5% and an average 5-year cohort increase of 7.8% (P = 0.025). The incidence in white children (19.2 per 100,000 per year) was 48% higher than in the previous cohort. Children aged 0-4 years had a 70% higher incidence (12.2 per 100,000 per year) than the original cohort; this increase was most marked in young black children. The overall age-adjusted incidence of type 2 diabetes was 5.8 per 100,000 per year and was significantly higher in black children.

CONCLUSIONS

The incidence of type 1 diabetes is rising among children in Philadelphia. The incidence rate has increased by 29% since the 1985-1989 cohort. The most marked increases were among white children ages 10-14 years and black children ages 0-4 years. The incidence of type 1 diabetes is 18 times higher than that of type 2 in white children but only 1.6 times higher in black children.

Comparison of oral and intravenous glucose tolerance test derived sensitivity and secretory indices in obese adolescents

BACKGROUND

Insulin resistance increases type 2 diabetes risk in obese adolescents. Thus, quantitative tools measuring insulin sensitivity and secretion are important for risk assessment.

METHODS

Forty-four obese pubertal adolescents underwent oral glucose tolerance test (OGTT) and frequently sampled intravenous glucose tolerance test (FSIGT). We correlated OGTT-derived whole body sensitivity index (WBISI) with FSIGT-derived insulin sensitivity index (Si). Insulinogenic index (IGI) from OGTT was compared with acute insulin response to glucose (AIRg) from FSIGT.

RESULTS

Fasting insulin (r = -.64, P < .0005) and glucose (r = -.39 P ≤ .0005) predicted Si. The OGTT-derived index WBISI correlated with the FSIGT-derived Si (r = .608, P < .0005). IGI correlated with AIRg from FSIGT (r = .704, P < .0005).

CONCLUSIONS

OGTT-based measures correlated with FSIGT-derived measures of insulin sensitivity and secretion. In particular, we demonstrated that WBISI can be a reliable alternative to FSIGT-derived Si in clinical settings where OGTT is a more feasible option.

Prediabetic obese adolescents have a more atherogenic lipoprotein profile compared with normoglycemic obese peers

OBJECTIVE

To compare lipoprotein profiles of prediabetic to normoglycemic obese adolescents.

STUDY DESIGN

Cross-sectional study of 95 obese, pubertal adolescents (12-17 years), who underwent oral glucose tolerance test, lipid panel, and lipoprotein subclass particle analysis (nuclear magnetic resonance spectroscopy). Univariate and linear regression analyses compared prediabetic and normoglycemic groups.

RESULTS

Of 95 obese adolescents enrolled in the study, 22.1% (n = 21) had prediabetes. They were similar to normoglycemic adolescents (n = 74) in age, race, body mass index, standard lipids, total low-density lipoprotein particles (LDL-P), and total high-density lipoprotein particles (HDL-P). However, prediabetics had higher concentrations of small LDL-P (714.0 ± 288.0 vs 537.7 ± 266.5 nmol/L, P = .01) and smaller LDL-P size (20.73 ± 0.41 vs 21.18 ± 0.65 nm, P = .003), than normoglycemic youth. Prediabetics had higher small HDL-P (18.5 ± 3.8 vs 16.6 ± 3.9 umol/L, P = .046), lower large HDL-P (4.49 ± 2.0 vs 6.32 ± 2.6 umol/L, P = .004), and smaller HDL-P size (8.73 ± 0.31 vs 9.01 ± 0.39 nm, P = .003). After adjusting for demographics, Tanner stage, and body mass index using multiple linear regression, all differences remained significant except for small HDL-P. After additional adjustment for Homeostasis Model Assessment-Insulin Resistance Index, only LDL-P size difference remained significant.

CONCLUSION

Obese prediabetic adolescents have a significantly more atherogenic lipoprotein profile compared with obese normoglycemic peers. Prediabetic adolescents may benefit from more aggressive interventions to decrease future cardiovascular risk.

Sleep architecture and glucose and insulin homeostasis in obese adolescents

OBJECTIVE

Sleep deprivation is associated with increased risk of adult type 2 diabetes mellitus (T2DM). It is uncertain whether sleep deprivation and/or altered sleep architecture affects glycemic regulation or insulin sensitivity or secretion. We hypothesized that in obese adolescents, sleep disturbances would associate with altered glucose and insulin homeostasis.

RESEARCH DESIGN AND METHODS

This cross-sectional observational study of 62 obese adolescents took place at the Clinical and Translational Research Center and Sleep Laboratory in a tertiary care children's hospital. Subjects underwent oral glucose tolerance test (OGTT), anthropometric measurements, overnight polysomnography, and frequently sampled intravenous glucose tolerance test (FSIGT). Hemoglobin A(1c) (HbA(1c)) and serial insulin and glucose levels were obtained, indices of insulin sensitivity and secretion were calculated, and sleep architecture was assessed. Correlation and regression analyses were performed to assess the association of total sleep and sleep stages with measures of insulin and glucose homeostasis, adjusted for confounding variables.

RESULTS

We found significant U-shaped (quadratic) associations between sleep duration and both HbA(1c) and serial glucose levels on OGTT and positive associations between slow-wave sleep (N3) duration and insulin secretory measures, independent of degree of obesity, pubertal stage, sex, and obstructive sleep apnea measures.

CONCLUSIONS

Insufficient and excessive sleep was associated with short-term and long-term hyperglycemia in our obese adolescents. Decreased N3 was associated with decreased insulin secretion. These effects may be related, with reduced insulin secretory capacity leading to hyperglycemia. We speculate that optimizing sleep may stave off the development of T2DM in obese adolescents.

Depressive symptoms and quality of life in adolescents with type 2 diabetes: baseline data from the TODAY study

OBJECTIVE

The study objective was to examine the prevalence of depressive symptoms and relationships to quality of life and demographics in the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) study's large, ethnically diverse youth with type 2 diabetes.

RESEARCH DESIGN AND METHODS

A total of 704 youth with type 2 diabetes <2 years' duration, aged 10-17 years, and BMI ≥85th percentile completed depressive symptoms and quality of life measures.

RESULTS

Some 14.8% reported clinically significant depressive symptoms, and older girls had significantly higher rates than older boys.

CONCLUSIONS

Rates of significant depressive symptoms were similar to those of healthy adolescents and lower than those of teens with type 1 diabetes. Elevated depressive symptoms, particularly in older girls, suggest clinicians assess vulnerability.

Meal replacements in the treatment of adolescent obesity: a randomized controlled trial

Use of meal replacements (MRs) in lifestyle modification programs (LMPs) for obese adults significantly increases weight loss, compared with prescription of an isocaloric conventional diet (CD). This 12-month randomized trial examined 113 obese adolescents (mean ± s.d. age of 15.0 ± 1.3 years and BMI of 37.1 ± 5.1 kg/m2) who were assigned to a LMP, combined with meal plans of 1300-1500 kcal/day of CD (self-selected foods) or MR (three SlimFast shakes, one prepackaged meal, five vegetable/fruit servings). After month 4 (phase 1), participants originally treated with MR were unmasked to their phase 2 (months 5-12) random assignment: continued use of MR (i.e., MR+MR) or transitioned to CD (i.e., MR+CD). Participants initially treated with CD in phase 1, continued with CD (i.e., CD). All three groups were treated for an additional 8 months (phase 2). Regression models were used to evaluate percentage change in BMI from baseline to month 4 (phase 1), months 5-12 (phase 2), and baseline to month 12. At month 4, participants assigned to MR (N = 65) achieved a mean (±s.e.) 6.3 ± 0.6% reduction in BMI, compared to a significantly (P = 0.01) smaller 3.8 ± 0.8% for CD participants (N = 37). In phase 2, BMI increased significantly (P < 0.001) in all three conditions, resulting in no significant (P = 0.39) differences between groups in percentage change in BMI at month 12. Across groups, mean reduction in BMI from baseline to month 12 was 3.4 ± 0.7% (P < 0.01). Use of MR significantly improved short-term weight loss, compared with CD, but its continued use did not improve maintenance of lost weight.

Adiponectin is associated with favorable lipoprotein profile, independent of BMI and insulin resistance, in adolescents

CONTEXT

Children with obesity and insulin resistance (IR) have decreased adiponectin and have increased cardiovascular risk. Adiponectin has antiatherogenic effects, but its mechanism is unclear.

OBJECTIVES

Our objectives were 1) to compare lipoprotein subclass particles among obese and lean adolescents and delineate their relationships with IR and 2) to measure relationships between adiponectin and lipoproteins and their dependence on body mass index (BMI) and/or IR. DESIGN, SETTING, PATIENTS, AND MAIN OUTCOME MEASURES: This was a cross-sectional study of 57 obese and 38 lean pubertal adolescents, measuring lipoprotein subclass particles (nuclear magnetic resonance spectroscopy), lipids, adiponectin, and homeostasis model assessment of IR (HOMA-IR).

RESULTS

Obese had higher low-density lipoprotein (LDL) cholesterol (P = 0.018), higher small LDL particles (LDL-P) (P < 0.0005), smaller LDL-P size (P < 0.0005), smaller high-density lipoprotein particle (HDL-P) size (P < 0.0005), lower HDL cholesterol (HDL-C) (P < 0.0005), and higher small HDL-P (P = 0.009) compared with lean. HOMA-IR was higher in obese than lean (P < 0.0005) and positively associated with triglycerides, large very LDL-P, and small HDL-P and negatively with HDL-P size in obese. Adiponectin was lower in obese than lean (P < 0.0005) and was positively associated with LDL-P size, HDL-P size, and HDL-C and negatively with triglycerides, small LDL-P, large very LDL-P, and small HDL-P in obese. Using linear regression adjusting for demographics, Tanner stage, BMI, and HOMA-IR in all adolescents, adiponectin was positively associated with LDL-P size (P = 0.028), HDL-P size (P < 0.0005), and HDL-C (P = 0.042) and negatively with small LDL-P (P = 0.009) and small HDL-P (P = 0.004).

CONCLUSIONS

Obese adolescents have lower adiponectin levels than lean, and a more atherogenic lipoprotein profile, associated with increased IR. Adiponectin was inversely associated with atherogenic lipoproteins in adolescents, even after adjusting for obesity and IR. This is the first such report in children, and suggests a relationship between adiponectin and lipoproteins in adolescents independent of BMI and IR.

Metabolic effects of obesity causing disease in childhood

PURPOSE OF REVIEW

Childhood obesity is rising to epidemic proportions throughout the world, and much emphasis has been placed on the long-term consequences that can result later, in adulthood. This article reviews the metabolic consequences of obesity that can manifest as disease during the childhood years.

RECENT FINDINGS

Obese children suffer from many disease processes once thought to affect only adults. They can have type 2 diabetes mellitus, and potentially early β cell failure with rapid progression to an insulin requirement. There is a high prevalence of fatty liver disease in obese children, and complications such as steatohepatitis and even cirrhosis can develop during childhood. Visceral fat has been shown to have many different properties than subcutaneous fat, and children with central adiposity can develop the metabolic syndrome with insulin resistance, hypertension, and dyslipidemia. Hyperandrogenism, sleep disturbances, and many types of orthopedic complications can also develop in young children.

SUMMARY

Physicians should not only warn obese children and their families about the long-term consequences of obesity for which they are at risk in adulthood, they should also screen for the many diseases that may already be present.

Increased prevalence of abnormal glucose tolerance among obese siblings of children with type 2 diabetes

OBJECTIVE

To test the hypothesis that overweight siblings of children with type 2 diabetes mellitus (T2DM) have a higher prevalence of abnormal glucose tolerance (AGT) compared with other overweight children.

STUDY DESIGN

This was a cross-sectional study of overweight (body mass index [BMI] >or= 95(th) percentile) subjects, age 8 to 17 years, with at least 1 sibling age >or= 12 years. The primary outcome was AGT, as assessed by the oral glucose tolerance test (2-hour glucose >or= 140 mg/dL). The secondary outcome was insulin resistance by homeostasis model assessment (HOMA).

RESULTS

The sibling (n=20) and control (n=42) groups were similar in terms of age, sex, racial distribution (largely African American), pubertal status, and BMI. The prevalence of AGT in the sibling group was 40.0% (n=8), compared with 14.3% (n=6) in controls (P= .048, Fisher exact test; unadjusted odds ratio=4.0; 95% confidence interval=1.2 to 13.5). Univariate analysis did not identify confounders for either outcome. There were no significant differences in HOMA or hemoglobin A1c between the 2 groups.

CONCLUSIONS

Overweight siblings of children with T2DM had 4 times greater odds of having AGT compared with other overweight children. This group may represent a particularly high-risk population to target for screening and pediatric T2DM prevention.

Increased glucagon-like peptide-1 secretion and postprandial hypoglycemia in children after Nissen fundoplication

CONTEXT

Postprandial hypoglycemia (PPH) is a frequent complication of Nissen fundoplication in children. The mechanism responsible for the PPH is poorly understood, but involves an exaggerated insulin response to a meal and subsequent hypoglycemia. We hypothesize that increased glucagon-like peptide-1 (GLP-1) secretion contributes to the exaggerated insulin surge and plays a role in the pathophysiology of this disorder.

OBJECTIVE

The aim of the study was to characterize glucose, insulin, and GLP-1 response to an oral glucose load in children with symptoms of PPH after Nissen fundoplication.

DESIGN

Ten patients with suspected PPH and a history of Nissen fundoplication and eight control subjects underwent a standard oral glucose tolerance test at The Children's Hospital of Philadelphia. Blood glucose (BG), insulin, and intact GLP-1 levels were obtained at various time points.

PARTICIPANTS

Children ages 4 months to 13 years old were studied.

MAIN OUTCOME MEASURES

Change scores for glucose, insulin, and intact GLP-1 were recorded after an oral glucose tolerance test.

RESULTS

All cases had hypoglycemia after the glucose load. Mean BG at nadir (+/- sd) was 46.7 +/- 11 mg/dl for cases (vs. 85.9 +/- 21.3 mg/dl; P < 0.0005). Mean change in BG from baseline to peak (+/- sd) was 179.3 +/- 87.4 mg/dl for cases (vs. 57.8 +/- 39.5 mg/dl; P = 0.003). Mean change in BG (+/- sd) from peak to nadir was 214.4 +/- 85.9 mg/dl for cases (vs. 55.9 +/- 41.1 mg/dl, P < 0.0005). Mean change in insulin (+/- sd) from baseline to peak was 224.3 +/- 313.7 microIU/ml for cases (vs. 35.5 +/- 22.2 microIU/ml; P = 0.012). Mean change in GLP-1 (+/- sd) from baseline to peak was 31.2 +/- 24 pm (vs. 6.2 +/- 9.5 pm; P = 0.014).

CONCLUSIONS

Children with PPH after Nissen fundoplication have abnormally exaggerated secretion of GLP-1, which may contribute to the exaggerated insulin surge and resultant hypoglycemia.

Fasting c-peptide and insulin-like growth factor-binding protein-1 levels help to distinguish childhood type 1 and type 2 diabetes at diagnosis

BACKGROUND

Children with new onset diabetes (n = 175) were evaluated over 12-months. Patients were presumptively diagnosed with type 2 diabetes mellitus (T2DM) (n = 26) based on obesity, a relative with T2DM, the ability to wean from insulin, and absence of glutamic acid decarboxylase-65 (GAD-65) antibodies. We hypothesized that markers of insulinization at diagnosis, including fasting C-peptide and insulin-like growth factor-binding protein (IGFBP)-1, in addition to initial CO(2) levels and urine ketones, would help in distinguishing type 1 diabetes mellitus (T1DM) from T2DM.

RESULTS

Children with T1DM (84 male, 65 female) had a mean age of 8.7 +/- 4.3 yr and a racial background of 78% white, 19% black, and 3% other. In contrast, children with T2DM (13 female, 13 male) had a mean age of 14.2 +/- 3.1 yr with a racial background of 58% black, 27% white, and 15% other. Fasting C-peptide level was 0.38 +/- 0.37 ng/mL in T1DM vs. 2.66 +/- 2.14 ng/mL in T2DM; a C-peptide of 0.85 ng/mL had 83% sensitivity in distinguishing T1DM from T2DM. Fasting IGFBP-1 level was 38.1 +/- 39.1 ng/mL (T1DM) vs. 3.6 +/- 4.5 ng/mL (T2DM); a value of 3.6 ng/dL could distinguish the two types of diabetes with 93% sensitivity. Urinary ketones were found in 79% of children with T1DM compared with 56% of those with T2DM, and the magnitude was associated with type of diabetes. Initial CO(2) level for T1DM was 17.9 +/- 6.9 mmol/L vs. 22.7 +/- 5.7 mmol/L for T2DM; a value of 21.5 mmol/L could distinguish the two types of diabetes with 83% sensitivity.

CONCLUSIONS

In addition to obesity, family history of T2DM, and absence of GAD-65 antibodies, children with new-onset T2DM may be distinguished from those with T1DM by a combination of biochemical parameters (C-peptide, IGFBP-1, CO(2), and urine ketones).

Leptin levels decline steadily during prolonged fasting in lean children

OBJECTIVE

To evaluate the effects of fasting on serum leptin levels in lean children.

STUDY DESIGN

Seventeen children, age 7.7 +/- 4.3 years with mean body mass index (BMI) of 16.7 +/- 2.7 kg/m(2), underwent standard diagnostic fasts for suspected hypoglycemia. Blood was sampled at 6-hour intervals for glucose, insulin, C-peptide, leptin, free and total insulin-like growth factor-1, insulin-like growth factor-binding protein-1, growth hormone, cortisol, ketones, and free fatty acids.

RESULTS

Subjects fasted 15 to 40 hours, and initial leptin levels were related to BMI and age. Leptin declined by 0.5 ng/mL per each fasting hour (P = .008), using a longitudinal mixed effects model. Leptin dropped significantly from an initial mean +/- SEM during the first 6 hours of 15.9 +/- 5.5 ng/mL to 3.5 +/- 0.9 ng/mL at the end of fasting. Mixed longitudinal effects models demonstrated that leptin was significantly related to insulin over time (P < .0001) as well as C-peptide (P < .0001). Significant relations were also seen with total insulin-like growth factor-1 over time, beta-hydroxybutyrate and insulin, and insulin-like growth factor-binding protein-1 and insulin.

CONCLUSIONS

After 6 hours, leptin levels steadily decline during prolonged fasting in lean children. The decline probably is related to the suppression of insulin secretion. Although baseline leptin levels were related to BMI and age, in the final fasting sample, leptin levels showed minimal variation in this pediatric cohort encompassing a wide age range.

Incidence of type 1 diabetes in Philadelphia is higher in black than white children from 1995 to 1999: epidemic or misclassification?

OBJECTIVE

To determine the epidemiology of type 1 diabetes in children in Philadelphia, Pennsylvania, from 1995 through 1999 and compare these data with previous cohorts.

RESEARCH DESIGN AND METHODS

This is a report of a retrospective population-based registry maintained since 1985. Hospital records meeting the following criteria were reviewed: newly diagnosed type 1 diabetes, age 0-14 years, residing in Philadelphia at the time of diagnosis, and diagnosed from 1 January 1995 to 31 December 1999. The secondary source of validation was the School District of Philadelphia. Incidence rates by race and age were compared with 1985-1989 and 1990-1994 cohorts.

RESULTS

A total of 234 case subjects were identified, and the registry was determined to be 96% complete. The overall age-adjusted incidence rate in Philadelphia was 14.8 per 100,000/year. Incidence rates in Hispanic children (15.5 per 100,000/year) and white children (12.8 per 100,000/year) have been relatively stable over 15 years. The incidence in black children (15.2 per 100,000/year), however, has increased dramatically, rising 64% in children 5-9 years of age (14.9 per 100,000/year) and 37% in the 10- to 14-year age-group (26.9 per 100,000/year).

CONCLUSIONS

The overall incidence of type 1 diabetes in Philadelphia is increasing and is similar to other U.S. registries. These are the first data reporting a higher incidence in black children in a registry of children 0-14 years of age. The etiology of the marked increase in incidence in the black population is unknown and underscores the need to establish type 1 diabetes as a reportable disease, so that environmental risk factors may be thoroughly investigated.

Hyperglycemic hyperosmolar non-ketotic syndrome in children with type 2 diabetes*

OBJECTIVE

Hyperglycemic hyperosmolar non-ketotic (HHNK) syndrome is thought to be a rare entity in the pediatric population, associated with significant mortality based on case reports in the literature. As obesity and type 2 diabetes in childhood grow in prevalence, such related complications may also increase. This study will serve to provide updated information regarding typical clinical course and sequelae of HHNK syndrome in childhood.

METHODS

Patients diagnosed with type 2 diabetes at Children's Hospital of Philadelphia (CHOP) over a period of 5 yr were screened retrospectively for any laboratory evidence of previous episodes of HHNK syndrome. The standard diagnostic criteria of blood glucose >600 mg/dL and serum osmolality >330 mOsm/L with only mild acidosis (serum bicarbonate >15 mmol/L and small ketonuria 15 mg/dL or less) were utilized.

RESULTS

The records of all patients with type 2 diabetes mellitus (DM) diagnosed over a 5-yr period were reviewed (n=190). Seven patients were found to have one episode of HHNK syndrome by diagnostic criteria (five males, mean age at presentation 13.3 yr, age range 10.1--16.9 yr), yielding a frequency of 3.7%. All were African-American. HHNK syndrome was the clinical presentation at diagnosis of new onset diabetes for all seven children. Three of seven children had a previously diagnosed developmental delay. The average Glasgow Coma Scale (GCS) score at presentation was 13 (range 9--15). Mean body mass index (BMI) at presentation was 32.7 kg/m(2) (n=6). Mean serum osmolality was 393 mOsm/L (n=7), and mean blood glucose was 1604 mg/dL (n = 7). The average time until mental status returned to baseline among survivors was 3 d (range 1--7 d). The average number of hospital days for survivors was 10 (range 5--24 d). Four of seven patients had an uncomplicated course. One patient developed multisystem organ failure and died on hospital day 4. The case fatality rate was 14.3% (one of seven). Survivors had no appreciable neurodevelopmental sequelae.

CONCLUSIONS

This retrospective chart review provides updated information regarding the entity of HHNK syndrome in children. This study supports the need for increased awareness of type 2 diabetes in children so that morbidity and mortality related to HHNK syndrome can be prevented.

Neuropsychiatric disorders at the presentation of type 2 diabetes mellitus in children

OBJECTIVES

To estimate the frequency of neuropsychiatric disease (NPD) in an urban pediatric type 2 diabetes mellitus (T2DM) population, to compare demographic characteristics of affected patients with those unaffected with NPD, and to determine the frequency of psychotropic medication treatment.

STUDY DESIGN

Retrospective chart review of patients with T2DM at the Children's Hospital of Philadelphia.

RESULTS

Of 237 patients with T2DM, 46 (19.4%) were found to have NPD at the presentation of diabetes. Diagnoses by report included depression, attention-deficit hyperactivity disorder (ADHD), neurodevelopmental disorders, schizophrenia, and bipolar disorder. Those affected were 63% females and 37% males, with a mean age of 14.6 yr and body mass index (BMI) of 34.3 kg/m(2) at diagnosis of T2DM. Patients were 79% African American, 13% Caucasian, 4.3% Hispanic, and 4.3% Asian. There were no statistically significant differences in demographic characteristics or BMI between those affected and unaffected with NPD. Twenty-nine patients (63%) were on psychotropic medication and were prescribed 58 medications, most commonly mood stabilizers (n = 20) and atypical antipsychotics (n = 17).

CONCLUSIONS

Our data reveal a high frequency of NPD among pediatric patients with T2DM at presentation to a tertiary care, urban medical center. Many affected patients are receiving psychotropic medication. These data have implications for screening regimens for pediatric populations at high risk for T2DM and for therapeutic interventions, including lifestyle measures.

Pharmacodynamic considerations with recombinant human insulin-like growth factor-I in children

AIM

To report effects of weight-based recombinant human insulin-like growth factor-I (rhIGF-I) on IGF axis parameters in children with hyperinsulinism.

METHODS

Open label trial with subcutaneous rhIGF-I (40 microg/kg/dose). Patients studied were children (1 month to 11 years) with diffuse hyperinsulinism (n = 7). Serial serum IGF and insulin-like growth factor binding protein (IGFBP) concentrations were measured by RIA and analyzed by linear Pearson regression.

RESULTS

Following the initial rhIGF-I dose, total insulin-like growth factor-I (IGF-I) rose by 56% at 30 min (p < 0.01) and 85% at 120 min (p < 0.02). Serum IGF-II, IGFBP-2, and IGFBP-3 levels did not change. Peak serum IGF-I levels within 12 h of the initial rhIGF-I dose were 167-700 mg/ml. The variable peak IGF-I response is attributable in part to IGFBP-3 differences across this pediatric age range. Models of rhIGF-I dosing based upon body surface area (BSA) or initial IGFBP-3 resulted in predictable peak serum IGF-I levels (r = 0.78; p < 0.03). Recalculating rhIGF-I dosing based upon the BSA . IGFBP-3 product correlated closely with peak IGF-I level (r = 0.85; p < 0.007).

CONCLUSIONS

Weight-based IGF-I dosing in this cohort resulted in variable IGF-I levels. Considering BSA and serum IGFBP-3 concentration in children is appropriate for subcutaneous IGF-I administration. A combination of these values may yield predictable individualization of rhIGF-I dosing.