Jihua Xu

Utility of waist-to-height ratio in assessing the status of central obesity and related cardiometabolic risk profile among normal weight and overweight/obese children: The Bogalusa Heart Study

BackgroundBody Mass Index (BMI) is widely used to assess the impact of obesity on cardiometabolic risk in children but it does not always relate to central obesity and varies with growth and maturation. Waist-to-Height Ratio (WHtR) is a relatively constant anthropometric index of abdominal obesity across different age, sex or racial groups. However, information is scant on the utility of WHtR in assessing the status of abdominal obesity and related cardiometabolic risk profile among normal weight and overweight/obese children, categorized according to the accepted BMI threshold values.MethodsCross-sectional cardiometabolic risk factor variables on 3091 black and white children (56% white, 50% male), 4-18 years of age were used. Based on the age-, race- and sex-specific percentiles of BMI, the children were classified as normal weight (5th - 85th percentiles) and overweight/obese (≥ 85th percentile). The risk profiles of each group based on the WHtR (<0.5, no central obesity versus ≥ 0.5, central obesity) were compared.Results9.2% of the children in the normal weight group were centrally obese (WHtR ≥0.5) and 19.8% among the overweight/obese were not (WHtR < 0.5). On multivariate analysis the normal weight centrally obese children were 1.66, 2.01, 1.47 and 2.05 times more likely to have significant adverse levels of LDL cholesterol, HDL cholesterol, triglycerides and insulin, respectively. In addition to having a higher prevalence of parental history of type 2 diabetes mellitus, the normal weight central obesity group showed a significantly higher prevalence of metabolic syndrome (p < 0.0001). In the overweight/obese group, those without central obesity were 0.53 and 0.27 times less likely to have significant adverse levels of HDL cholesterol and HOMA-IR, respectively (p < 0.05), as compared to those with central obesity. These overweight/obese children without central obesity also showed significantly lower prevalence of parental history of hypertension (p = 0.002), type 2 diabetes mellitus (p = 0.03) and metabolic syndrome (p < 0.0001).ConclusionWHtR not only detects central obesity and related adverse cardiometabolic risk among normal weight children, but also identifies those without such conditions among the overweight/obese children, which has implications for pediatric primary care practice.

Utility of Childhood Non–High-Density Lipoprotein Cholesterol Levels in Predicting Adult Dyslipidemia and Other Cardiovascular Risks: The Bogalusa Heart Study

OBJECTIVE. This study sought to examine the usefulness of non–high-density lipoprotein cholesterol levels in predicting future dyslipidemia and other cardiovascular risk in adulthood. METHODS. The study sample consisted of a longitudinal cohort of subjects (n = 1163; 30.1% black and 55.4% female) who participated in the Bogalusa Heart Study both as children at 5 to 14 years of age and as adults 27 years later. RESULTS. The childhood level of non–high-density lipoprotein cholesterol, like low-density lipoprotein cholesterol, was the best predictor of the adulthood level; the next best predictor for both variables was the change in BMI from childhood to adulthood. Furthermore, those in the age-, race-, and gender-specific top quartile, compared with those in the bottom quartile, of non–high-density lipoprotein cholesterol and low-density lipoprotein cholesterol levels in childhood were 4.5 and 3.5 times more likely, respectively, to develop adult dyslipidemia, independent of baseline BMI and BMI change after 27 years. Although, at equivalent cutoff points, childhood high-risk versus acceptable-risk status for both lipid measures was associated significantly with increased prevalence of obesity and adverse levels of low-density lipoprotein cholesterol and triglycerides in adulthood, only childhood non–high-density lipoprotein cholesterol high-risk status was associated with increased prevalence of low high-density lipoprotein cholesterol levels, hyperinsulinemia, and hyperglycemia (marginal). CONCLUSIONS. Adverse levels of non–high-density lipoprotein cholesterol versus low-density lipoprotein cholesterol in childhood not only equally persist over time and better predict adult dyslipidemia but also are related to nonlipid cardiovascular risk factors in adulthood.

Changes in Risk Variables of Metabolic Syndrome Since Childhood in Pre-Diabetic and Type 2 Diabetic Subjects: The Bogalusa Heart Study

OBJECTIVE—That type 2 diabetes is associated with the metabolic syndrome is known. However, information is lacking regarding the long-term and adverse changes of metabolic syndrome variables in the development of type 2 diabetes from childhood to adulthood. RESEARCH DESIGN AND METHODS—Observations were examined, retrospectively, in a community-based cohort of normoglycemic (n = 1,838), pre-diabetic (n = 90), and type 2 diabetic (n = 60) subjects followed serially for cardiovascular risk factors during childhood (4–11 years), adolescence (12–18 years), and adulthood (19–44 years). RESULTS—Diabetic subjects versus normoglycemic subjects had significantly higher levels of subscapular skinfold, BMI, triglycerides, glucose, insulin, and homeostasis model assessment of insulin resistance and lower levels of HDL cholesterol beginning in childhood and higher levels of mean arterial pressure (MAP) in adolescence and adulthood. In a multivariate model including BMI, MAP, HDL cholesterol, LDL cholesterol, triglycerides, glucose, and insulin, adjusted for age, age2, race, sex, and race × sex interaction, adverse changes in glucose and LDL cholesterol were independently associated with pre-diabetic subjects, whereas adverse changes in BMI, glucose, and HDL cholesterol were associated with diabetic subjects. As young adults, pre-diabetic and diabetic groups displayed a significantly higher prevalence of obesity, hypertension, dyslipidemia, hyperinsulinemia, and metabolic syndrome. CONCLUSIONS—These findings indicate that adverse levels of risk variables of metabolic syndrome, adiposity, and measures of glucose homeostasis accelerating since childhood characterize the early natural history of type 2 diabetes and underscore the importance of early prevention and intervention on risk factors beginning in childhood.

Usefulness of childhood non-high density lipoprotein cholesterol levels versus other lipoprotein measures in predicting adult subclinical atherosclerosis: the Bogalusa Heart Study.

OBJECTIVE. This study sought to examine the usefulness of childhood non–high-density lipoprotein cholesterol level versus low-density lipoprotein cholesterol level, high-density lipoprotein cholesterol level, triglyceride level, apolipoprotein B level, apolipoprotein A-I level, total cholesterol/high-density lipoprotein cholesterol ratio, and apolipoprotein B/apolipoprotein A-I ratio in predicting adult excess carotid intima-media thickness, an indicator of subclinical atherosclerosis. METHODS. This retrospective cohort study included 437 black and white subjects (70% white and 40% male) who participated in the Bogalusa Heart Study as children 5 to 17 years of age and as adults 16 to 19 years later. RESULTS. In analyses of each lipoprotein measure as a risk factor for predicting excess carotid intima-media thickness in adulthood, non–high-density lipoprotein cholesterol level, low-density lipoprotein cholesterol level, total cholesterol/high-density lipoprotein cholesterol ratio, apolipoprotein B level, and apolipoprotein B/apolipoprotein A-I ratio emerged as significant predictors, with respective odds ratios of 2.60, 2.95, 1.78, 1.44, and 1.69, after adjustment for childhood BMI, systolic blood pressure, other lipoprotein measures, and follow-up years; the odds ratios for high-density lipoprotein cholesterol, triglyceride, and apolipoprotein A-I levels were not significant. Regarding the discriminating value of different childhood lipoprotein measures in predicting excess carotid intima-media thickness in adulthood, analyses of the area under the receiver operating characteristic curve for each lipoprotein measure, adjusted for the aforementioned nonlipoprotein covariates, indicated that the value of 0.65 for the non–high-density lipoprotein cholesterol level was similar in magnitude to those for other lipoprotein measures, with values ranging from 0.62 to 0.66. CONCLUSIONS. Childhood non–high-density lipoprotein cholesterol levels are as good as other lipoprotein measures in predicting subclinical atherosclerosis in adulthood, which has practical implications for coronary artery disease risk assessment and intervention in pediatric populations.

Utility of waist-to-height ratio in detecting central obesity and related adverse cardiovascular risk profile among normal weight younger adults (from the Bogalusa Heart Study).

Data on the utility of the waist-to-height ratio in detecting central obesity and related cardiovascular risk among normal weight younger adults are scant. This aspect was examined in 639 normal weight (body mass index 18.5 to 24.9 kg/m(2)) black and white adults (75% white and 36% men) 20 to 44 years old. The subjects with a waist-to-height ratio > or =0.5 were grouped as having central obesity normal weight, with the rest considered the control group. The subjects with central obesity, compared to the controls, after adjusting for age, race, and gender, had significantly greater diastolic blood pressure, mean arterial pressure, low-density lipoprotein cholesterol level, triglycerides, triglycerides/high-density lipoprotein cholesterol ratio, insulin, homeostasis model assessment of insulin resistance, uric acid, C-reactive protein, and liver function enzymes (alanine aminotransferase and gamma-glutamyl transferase). On multivariate analysis, the central obesity group compared to the control group was 1.9, 2.2, 2.9, and 2.5 times more likely to have significantly adverse levels (top tertile vs the rest) of mean arterial pressure, triglycerides/high-density lipoprotein cholesterol ratio, homeostasis model assessment of insulin resistance, and C-reactive protein, respectively. The central obesity group also had a greater prevalence of dyslipidemia, hypertension, insulin resistance, hyperuricemia, and elevated C-reactive protein. The age-, race-, and gender-adjusted mean value of the common carotid intima-media thickness, a measure of subclinical atherosclerosis, was greater in the central obesity group compared to the control group (0.76 vs 0.71 mm, p = 0.009). In conclusion, these findings underscore the utility of the waist-to-height ratio in detecting central obesity and related adverse cardiovascular risk among normal weight younger adults.

Plasma Homocysteine Distribution and Its Association With Parental History of Coronary Artery Disease in Black and White Children The Bogalusa Heart Study

BACKGROUND Elevated homocysteine is associated with increased risk for coronary artery disease (CAD) in adults, but its distribution in children is not well documented. We examined the distribution of homocysteine in children and its relation to parental history of CAD. METHODS AND RESULTS A subsample of 1137 children (53% white, 47% black) aged 5 to 17 years in 1992 to 1994 examined in the Bogalusa Heart Study (n=3135), including all with a positive parental history of CAD (n=154), had plasma homocysteine levels measured. Homocysteine correlated positively with age (r=0.16, P=0.001). No race or sex differences in homocysteine levels were observed; geometric mean (GM) levels were 5.8 micromol/L (95% CI, 5.6 to 6.1) among white males, 5.8 micromol/L (95% CI, 5.5 to 6.0) among white females, 5.6 micromol/L (95% CI, 5.4 to 5.8) among black males, and 5.6 micromol/L (95% CI, 5.4 to 5.9) among black females. Children with a positive parental history of CAD had a significantly greater age-adjusted GM homocysteine level (GM, 6.7 micromol/L; 95% CI, 6.4 to 7.1) than those without a positive history (GM, 5.6 micromol/L; 95% CI, 5.4 to 5.7); this relation was observed in each race-sex group. CONCLUSIONS Higher homocysteine levels were observed among children with a positive family history of CAD. Additional studies should elucidate the contribution of genetic, dietary, and other factors to homocysteine levels in children.

A diagnosis of the metabolic syndrome in youth that resolves by adult life is associated with a normalization of high carotid intima-media thickness and type 2 diabetes mellitus risk: the Bogalusa heart and cardiovascular risk in young Finns studies.

OBJECTIVES The aim of this study was to examine the effect of resolution from metabolic syndrome (MetS) between youth and adulthood on carotid artery intima-media thickness (IMT) and type 2 diabetes mellitus (T2DM). BACKGROUND Published findings demonstrate that youth with MetS are at increased risk of cardio-metabolic outcomes in adulthood. It is not known whether this risk is attenuated in those who resolve their MetS status. METHODS Participants (n = 1,757) from 2 prospective cohort studies were examined as youth (when 9 to 18 years of age) and re-examined 14 to 27 years later. The presence of any 3 components (low high-density lipoprotein cholesterol, high triglycerides, high glucose, high blood pressure, or high body mass index) previously shown to predict adult outcomes defined youth MetS; the harmonized MetS criteria defined adulthood MetS. Participants were classified according to their MetS status at baseline and follow-up and examined for risk of high IMT and T2DM. RESULTS Those with MetS in youth and adulthood were at 3.4 times the risk (95% confidence interval: 2.4 to 4.9) of high IMT and 12.2 times the risk (95% confidence interval: 6.3 to 23.9) of T2DM in adulthood compared with those that did not have MetS at either time-point, whereas those that had resolved their youth MetS status by adulthood showed similar risk to those that did not have MetS at either time-point (p > 0.20 for all comparisons). CONCLUSIONS Although youth with MetS are at increased risk of adult high IMT and T2DM, these data indicate that the resolution of youth MetS by adulthood can go some way to normalize this risk to levels seen in those who have never had MetS.

Utility of childhood glucose homeostasis variables in predicting adult diabetes and related cardiometabolic risk factors: the Bogalusa Heart Study

OBJECTIVE This study examines the usefulness of childhood glucose homeostasis variables (glucose, insulin, and insulin resistance index [homeostasis model assessment of insulin resistance {HOMA-IR}]) in predicting pre-diabetes and type 2 diabetes and related cardiometabolic risk factors in adulthood. RESEARCH DESIGN AND METHODS This retrospective cohort study consisted of normoglycemic (n = 1,058), pre-diabetic (n = 37), and type 2 diabetic (n = 25) adults aged 19–39 years who were followed on average for 17 years since childhood. RESULTS At least 50% of the individuals who ranked highest (top quintile) in childhood for glucose homeostasis variables maintained their high rank by being above the 60th percentile in adulthood. In a multivariate model, the best predictors of adulthood glucose homeostasis variables were the change in BMI Z score from childhood to adulthood and childhood BMI Z score, followed by the corresponding childhood levels of glucose, insulin, and HOMA-IR. Further, children in the top decile versus the rest for insulin and HOMA-IR were 2.85 and 2.55 times, respectively, more likely to develop pre-diabetes; children in the top decile versus the rest for glucose, insulin, and HOMA-IR were 3.28, 5.54, and 5.84 times, respectively, more likely to develop diabetes, independent of change in BMI Z score, baseline BMI Z score, and total-to-HDL cholesterol ratio. In addition, children with adverse levels (top quintile versus the rest) of glucose homeostasis variables displayed significantly higher prevalences of, among others, hyperglycemia, hypertriglyceridemia, and metabolic syndrome. CONCLUSIONS Adverse levels of glucose homeostasis variables in childhood not only persist into adulthood but also predict adult pre-diabetes and type 2 diabetes and relate to cardiometabolic risk factors.

Relation of Childhood Obesity/Cardiometabolic Phenotypes to Adult Cardiometabolic Profile The Bogalusa Heart Study

Not all obese adults have cardiometabolic abnormalities. It is unknown whether this is true in children and, if true, whether children who have metabolically healthy overweight/obesity (MHO) will also have favorable cardiometabolic profiles in adulthood. These aspects were examined in 1,098 individuals who participated as both children (aged 5-17 years) and adults (aged 24-43 years) in the Bogalusa Heart Study between 1997 and 2002 in Bogalusa, Louisiana. MHO was defined as being in the top body mass index quartile, while low density lipoprotein cholesterol, triglycerides, mean arterial pressure, and glucose were in the bottom 3 quartiles, and high density lipoprotein cholesterol was in the top 3 quartiles. Forty-six children (4.2%) had MHO, and they were more likely to retain MHO status in adulthood compared with children in other categories (P < 0.0001). Despite markedly increased obesity in childhood and in adulthood, these same MHO children and adults showed a cardiometabolic profile generally comparable to that of nonoverweight/obese children (P > 0.05 in most cases). Moreover, there was no difference in carotid intima-media thickness in adulthood between MHO children and nonoverweight/obese children. Further, carotid intima-media thickness in adulthood was lower in MHO children than in metabolically abnormal, overweight/obese children (P = 0.003). In conclusion, the MHO phenotype starts in childhood and continues into adulthood.

Fasting Plasma Glucose Levels Within the Normoglycemic Range in Childhood as a Predictor of Prediabetes and Type 2 Diabetes in Adulthood: The Bogalusa Heart Study

OBJECTIVES To determine whether childhood elevated fasting plasma glucose (FPG) levels within the normoglycemic range predict diabetes in adulthood. DESIGN Retrospective cohort study. SETTING Community of Bogalusa, Louisiana. PARTICIPANTS Normoglycemic (n = 1723), prediabetic (n = 79), and type 2 diabetic (n = 47) adults aged 19 to 44 years followed up serially for an average of 21 years since childhood. Main Exposures Association of elevated baseline childhood FPG levels with the prediabetic or diabetic status at the last survey in adulthood. MAIN OUTCOME MEASURES Receiver operating characteristic analysis and longitudinal logistic regression odds ratios. RESULTS The prevalent rate of adult diabetes status by quartiles of baseline childhood FPG levels showed an adverse trend for prediabetes (P < .001) and diabetes (P = .03), with an apparent threshold occurring at or above the 50th percentile (86 mg/dL). Regarding the predictive value of the above threshold, the area under the receiver operating curve analysis yielded a C value of 0.855 for prediabetes and 0.789 for diabetes models, with sensitivity and specificity, respectively, of 76.9% and 85.2% for prediabetes and 75.0% and 76.0% for diabetes. In a multivariate analysis that included anthropometric, hemodynamic, and metabolic variables from childhood to adulthood and baseline childhood FPG status (> or = vs < 50th percentile), individuals with elevated childhood FPG levels were 3.40 times more likely to develop prediabetes (P < .001) and 2.06 times more likely to develop diabetes (P = .05) as adults. CONCLUSION The fact that elevated FPG level in childhood, even within the normoglycemic range, is a predictor of type 2 diabetes in younger adulthood has implications for health care policy.