Evidence for cryptic diversification in a rupicolous forest-dwelling gecko (Gekkonidae: Afroedura pondolia) from a biodiversity hotspot.

We assess the phylogeographic structure and test several species delimitation methods in the forest-living Pondo flat-gecko, Afroedura pondolia, by sampling specimens from across the entire distribution in the Eastern Cape and KwaZulu-Natal provinces of South Africa. Phylogenetic results, using Bayesian inferences and maximum likelihood, from the combined mitochondrial and nuclear DNA sequence data derived from four partial loci (ND4, cyt b, PRLR and RAG1), suggest the presence of four geographically discrete clades, which represent candidate species. We applied four species-delimitation methods (ABGD, bGMYC, PTP and STACEY), the results of which were largely incongruent in the number of putative species nested within A. pondolia. Multivariate morphological analyses indicate statistically significant differences among the four candidate species, corroborating the presence of four cryptic species within A. pondolia. Divergence-time estimates suggest that cladogenesis was driven by forest fragmentation from the late Miocene to the Plio/Pleistocene with the onset of more pronounced xeric climatic conditions causing forest fragmentation.

Lipid changes 8 years post gastric bypass in adolescents with severe obesity (FABS-5+ study).

OBJECTIVE: Severe obesity in adolescents is increasing and few effective treatments exist. Bariatric surgery is one option, but the extent to which surgery influences cardiovascular risk factors over time in youth is not clear. We hypothesized that Roux-en Y gastric bypass (RYGB) would be associated with sustained improvements in lipids over time (>5 years). PARTICIPANTS/METHODS: Youth who underwent RYGB from 2001 to 2007 were recruited for the Follow-up of Adolescent Bariatric Surgery-5+ (FABS-5+) in 2011-2014. Baseline body mass index (BMI) and lipids were abstracted from medical records. Follow-up data were obtained at a research visit. Analyses included paired t-tests to assess changes in BMI and lipids over time. General linear models were used to evaluate predictors of high-density lipoprotein (HDL) and non-HDL-cholesterol at follow-up. A non-operative group was recruited for comparison. RESULTS: Surgical participants (n=58) were a mean±s.d. age of 17±2 years at baseline and 25±2 years at long-term follow-up. Eighty-six percent were Caucasian and 64% were female. At long-term follow-up BMI decreased by 29% and all lipids (except total cholesterol) significantly improved (P<0.01). Female sex was a significant predictor of non-HDL-cholesterol level at 1 year, while change in BMI from 1 year to long-term follow-up was a significant predictor of non-HDL-cholesterol and HDL-cholesterol during the same interval (P<0.05). In the non-operative group, BMI increased by 8% and lipid parameters were unchanged. CONCLUSIONS: This is the longest and most complete follow-up of youth following RYGB. Weight loss maintenance over time was significantly associated with improvements in lipid profile over 5 years.

Comparing US paediatric and adult weight classification at the transition from late teenage to young adulthood.

BACKGROUND: Although paediatric growth charts are recommended for weight assessment prior to age 20, many teenagers transition earlier to adult care where absolute body mass index (BMI) is used. This study examines concordance of weight classification in older teenagers using paediatric percentiles and adult thresholds. METHODS: BMI from 23 640 US teens ages 18-19 years were classified using paediatric BMI percentile criteria for underweight (< 5th), normal (5th to < 85th), overweight (85th to < 95th), obesity (≥ 95th) and severe obesity (≥ 120% × 95th percentile) and adult BMI (kg m(-2) ) criteria for underweight (< 18.5), normal (18.5-24.9), overweight (25-29.9) and obesity: class I (30-34.9), class II (35-39.9) and class III (≥ 40). Concordance was examined using the kappa (κ) statistic. Blood pressure (BP) from the same visit was classified hypertensive for BP ≥ 140/90. RESULTS: The majority of visits (72.8%) occurred in adult primary care. Using paediatric/adult criteria, 3.4%/5.2% were underweight, 66.6%/58.8% normal weight, 15.7%/21.7% overweight, 14.3%/14.3% obese and 4.9%/6.0% severely/class II-III obese, respectively. Paediatric and adult classification for underweight, normal, overweight and obesity were concordant for 90.3% (weighted κ 0.87 [95% confidence interval, 0.87-0.88]). For severe obesity, BMI ≥ 120% × 95th percentile showed high agreement with BMI ≥ 35 kg m(-2) (κ 0.89 [0.88-0.91]). Normal-weight males and moderately obese females by paediatric BMI percentile criteria who were discordantly classified into higher adult weight strata had a greater proportion with hypertensive BP compared with concordantly classified counterparts. CONCLUSIONS: Strong agreement exists between US paediatric BMI percentile and adult BMI classification for older teenagers. Adult BMI classification may optimize BMI tracking and risk stratification during transition from paediatric to adult care.

Prevalence of obesity and extreme obesity in children aged 3-5 years.

BACKGROUND: Early childhood adiposity may have significant later health effects. This study examines the prevalence and recognition of obesity and severe obesity among preschool-aged children. METHODS: The electronic medical record was used to examine body mass index (BMI), height, sex and race/ethnicity in 42,559 children aged 3-5 years between 2007 and 2010. Normal or underweight (BMI < 85th percentile); overweight (BMI 85th-94th percentile); obesity (BMI ≥ 95th percentile); and severe obesity (BMI ≥ 1.2 × 95th percentile) were classified using the 2000 Centers for Disease Control and Prevention growth charts. Provider recognition of elevated BMI was examined for obese children aged 5 years. RESULTS: Among 42,559 children, 12.4% of boys and 10.0% of girls had BMI ≥ 95th percentile. The prevalence was highest among Hispanics (18.2% boys, 15.2% girls), followed by blacks (12.4% boys, 12.7% girls). A positive trend existed between increasing BMI category and median height percentile, with obesity rates highest in the highest height quintile. The prevalence of severe obesity was 1.6% overall and somewhat higher for boys compared with girls (1.9 vs. 1.4%, P < 0.01). By race/ethnicity, the highest prevalence of severe obesity was seen in Hispanic boys (3.3%). Among those aged 5 years, 77.9% of obese children had provider diagnosis of obesity or elevated BMI, increasing to 89.0% for the subset with severe obesity. CONCLUSIONS: Obesity and severe obesity are evident as early as age 3-5 years, with race/ethnic trends similar to older children. This study underscores the need for continued recognition and contextualization of early childhood obesity in order to develop effective strategies for early weight management.

Eating patterns and lipid levels in older adolescent girls.

BACKGROUND AND AIMS: Few studies have evaluated the effects of food-based eating patterns on adolescent lipid levels. This study examines whether usual adolescent eating patterns (ages 9-17 years) predict lipid levels at 18-20 years of age. METHODS AND RESULTS: This study uses previously collected data from the longitudinal NHLBI Growth and Health Study in which 2379 girls were enrolled at ages 9-10 years and followed for ten years. Food-based eating patterns were derived from multiple 3-day diet records. After adjusting for age, race, socioeconomic status, height, physical activity, and television viewing, girls with higher intakes of dairy, fruit and non-starchy vegetables had about a 40-50% reduced risk an LDL-C ≥ 170 mg/dL and non-HDL-C ≥ 145 mg/dL. Diets characterized by higher intakes of dairy and whole grains had similar benefits on TC and LDL-C. Girls consuming more fruits and non-starchy vegetables as well as more whole grains were much less likely to have high-risk lipid levels. Lean meat, poultry and fish when consumed in the context of other healthy eating patterns had no adverse effects on lipid levels in late adolescence. In fact when consumed with higher amounts of fruit and non-starchy vegetables, lean meat, poultry and fish had beneficial effects on HDL. Finally, dietary patterns that included more whole grains tended to be associated with lower TG levels. CONCLUSION: Healthy childhood eating patterns characterized by higher intakes of a variety of fruits, vegetables, whole grains, dairy, lean meat, poultry and fish are important modifiable predictors of lipid levels in late adolescence.

Phylogeography of the Cape velvet worm (Onychophora: Peripatopsis capensis) reveals the impact of Pliocene/Pleistocene climatic oscillations on Afromontane forest in the Western Cape, South Africa.

Habitat specialists such as soft-bodied invertebrates characterized by low dispersal capability and sensitivity to dehydration can be employed to examine biome histories. In this study, the Cape velvet worm (Peripatopsis capensis) was used to examine the impacts of climatic oscillations on historical Afromontane forest in the Western Cape, South Africa. Divergence time estimates suggest that the P. capensis species complex diverged during the Pliocene epoch. This period was characterized by dramatic climatic and topographical change. Subsequently, forest expansion and contraction cycles led to diversification within P. capensis. Increased levels of genetic differentiation were observed along a west-to-south-easterly trajectory because the south-eastern parts of the Cape Fold Mountain chain harbour larger, more stable fragments of forest patches, have more pronounced habitat heterogeneity and have historically received higher levels of rainfall. These results suggest the presence of three putative species within P. capensis, which are geographically discreet and genetically distinct.

Blood pressure elevation in long-term survivors of pediatric liver transplantation.

As pediatric liver transplant (LT) recipients come of age, additional insight into long-term medical complications of immunosuppression is warranted. The aims of this study were to estimate the prevalence of elevated blood pressure (BP) in long-term survivors of pediatric LT using the data from the Studies in Pediatric Liver Transplantation (SPLIT) database and to identify predictive factors. Patients enrolled in the BP arm of the SPLIT cohort participated in the study. All patients were of at least 5 years but ≤10 years post-LT. Automated BP measurements were obtained at anniversary visits. BP measures were classified as normal, borderline or elevated according to standard criteria. Patients taking antihypertensive medications were classified as "elevated." Eight hundred and fifteen patients participated. The prevalence of elevated BP measurements 5 to 10 years post-LT was 17.5 to 27.5%. Of total 62.5% patients presented with at least one additional elevated BP at a later follow up visit. Multivariate analysis revealed the following parameters to be predictive of elevated BP: age at transplant, steroid use at last BP measurement and cGFR at last BP measurement. Pediatric LT patients show a high prevalence of elevated BP measurements 5 to 10 years following LT, which is related to age at LT, decreased cGFR and recent steroid use.

Screening and treatment of dyslipidemias in children and adolescents.

BACKGROUND/AIMS: Cardiovascular disease is the most prominent cause of mortality worldwide. A key risk factor for atherosclerotic cardiovascular disease is the presence of dyslipidemia. Clinical approaches to evaluation and treatment of dyslipidemia in children and adolescents are presented. METHODS: A review of published guidelines and presentation of illustrative cases. RESULTS: Dyslipidemia is an important risk factor in early-stage atherosclerosis. Children and adolescents at high risk for dyslipidemia can be identified using a positive family history or the presence of other risk factors as a trigger. Once high-risk individuals are identified, primary treatment is lifestyle modification. In cases where low-density lipoprotein-cholesterol is high, pharmacologic intervention may be needed. CONCLUSIONS: Screening of appropriate children and adolescents for dyslipidemia and treating those at high risk are important for the long-term prevention of cardiovascular disease.

Association of insulin sensitivity to lipids across the lifespan in people with Type 1 diabetes.

AIMS: Insulin resistance and dyslipidaemia both increase cardiovascular risk in Type 1 diabetes. However, little data exist on the associations of insulin resistance to lipids in Type 1 diabetes. Our objective was to explore the associations between insulin resistance (assessed by glucose infusion rate) and lipids in people with Type 1 diabetes and determine whether adiposity and/or average glycaemia influence these associations. METHODS: Hyperinsulinaemic-euglycaemic clamp studies were performed in 60 subjects with Type 1 diabetes aged 12-19 years (age 15±2 years, 57% female, duration of diabetes 6.3±3.8 years, HbA(1c) 8.6±1.5%, IFCC=70 mmol/mol) and 40 subjects with Type 1 diabetes aged 27-61 years (age 45±9 years, 53% female, duration of diabetes 23±8 years, HbA(1c) 7.5±0.9%, IFCC=58 mmol/mol). Multiple linear regression models were fit to examine the association between glucose infusion rate and fasting lipid levels with adjustment for possible confounders. RESULTS: Lower glucose infusion rate was significantly associated with lower levels of HDL cholesterol in youths with Type 1 diabetes and with higher levels of triglycerides and higher triglyceride/HDL ratio in both youths and adults. The magnitude of the associations between glucose infusion rate and lipid levels translate into interquartile differences of 0.098 mmol/l for HDL cholesterol, 0.17 mmol/l for triglycerides and 1.06 for triglycerides/HDL in the adolescents and 0.20 mmol/l for triglycerides and 1.01 for triglycerides/HDL in the adults. The associations were attenuated and no longer statistically significant by adjustment for adiposity among adults, while adjustment for HbA(1c) had a small effect in youths and adults. CONCLUSIONS: Lower insulin sensitivity is associated with a more atherogenic lipid profile in both youths and adults with Type 1 diabetes.

Chromosomal polymorphisms in African vlei rats, Otomys irroratus (Muridae: Otomyini), detected by banding techniques and chromosome painting: inversions, centromeric shifts and diploid number variation.

Pericentric inversions are important for evolutionary biology because of their potential role in speciation. They may result in reproductive isolation due to illegitimate pairing of homologues at meiosis which leads to the production of aneuploid gametes (containing deletions or duplications of chromosomal segments), and consequently mediate chromosomal divergence. In this study, we describe the prevalence of pericentric inversions in the African vlei rat, Otomys irroratus (OIR). The species is characterized by intraspecific chromosomal variation (2n = 23-32) across its distribution in southern Africa. Here, we analyzed 55 individuals collected from 7 localities in South Africa by G- and C-banding and chromosome painting with flow sorts of Myotomys unisulcatus. Of the 55 specimens that were analyzed, 47% contained inversions or centromeric shifts on 4 autosomes (OIR1, 4, 6 and 10) which were present singly in specimens (i.e. none of the specimens contained all 4 inversions concurrently). These inversions were found in both homozygous and heterozygous state over a wide geographic range suggesting that they are floating polymorphisms. Given the potential role of inversions in post-mating isolation (through production of aneuploid gametes), the prevalence of inversions as floating polymorphisms in the vlei rats suggests that they are probably retained in the population through suppression of recombination in the inverted regions of the chromosomes.

The effects of obesity and type 2 diabetes mellitus on cardiac structure and function in adolescents and young adults.

AIMS/HYPOTHESIS: We sought to evaluate the effects of obesity and obesity-related type 2 diabetes mellitus on cardiac geometry (remodelling) and systolic and diastolic function in adolescents and young adults. METHODS: Cardiac structure and function were compared by echocardiography in participants who were lean, obese or obese with type 2 diabetes (obese diabetic), in a cross sectional study. Group differences were assessed using ANOVA. Independent determinants of cardiac outcome measures were evaluated with general linear models. RESULTS: Adolescents with obesity and obesity-related type 2 diabetes were found to have abnormal cardiac geometry compared with lean controls (16% and 20% vs <1%, p < 0.05). These two groups also had increased systolic function. Diastolic function decreased from the lean to obese to obese diabetic groups with the lowest diastolic function observed in the obese diabetic group (p < 0.05). Regression analysis showed that group, BMI z score (BMIz), group × BMIz interaction and systolic BP z score (BPz) were significant determinants of cardiac structure, while group, BMIz, systolic BPz, age and fasting glucose were significant determinants of the diastolic function (all p < 0.05). CONCLUSIONS/INTERPRETATION: Adolescents with obesity and obesity-related type 2 diabetes demonstrate changes in cardiac geometry consistent with cardiac remodelling. These two groups also demonstrate decreased diastolic function compared with lean controls, with the greatest decrease observed in those with type 2 diabetes. Adults with diastolic dysfunction are known to be at increased risk of progressing to heart failure. Therefore, our findings suggest that adolescents with obesity-related type 2 diabetes may be at increased risk of progressing to early heart failure compared with their obese and lean counterparts.

Association of glycaemia with lipids in adults with type 1 diabetes: modification by dyslipidaemia medication.

AIMS/HYPOTHESIS: Hyperglycaemia and dyslipidaemia are common metabolic abnormalities in adults with type 1 diabetes and both increase cardiovascular disease (CVD) risk. The hypothesis of this study was that change in HbA(1c) over 6 years would be associated with change in fasting lipids in adults with type 1 diabetes. METHODS: The Coronary Artery Calcification in Type 1 Diabetes (CACTI) study examined 652 patients with type 1 diabetes (54% female); 559 and 543 had follow-up visits at 3 and 6 years. Baseline age (mean ± SD) was 37 ± 9 years, diabetes duration 23 ± 9 years, and HbA(1c) 8.0 ± 1.3%. Use of dyslipidaemia medication was 17%, 32%, and 46% at the three visits. Separate longitudinal mixed models were fitted to examine the relationship between change in HbA(1c) and change in fasting total cholesterol (TC), HDL-cholesterol (HDL-c), LDL-cholesterol (LDL-c), log triacylglycerols (TG), and non-HDL-cholesterol (non-HDL-c). Because of an interaction between dyslipidaemia medication use and association of HbA(1c) with lipids, results were stratified by dyslipidaemia medication use. RESULTS: Among patients not using dyslipidaemia medication, a higher HbA(1c) was associated with significantly worse levels of the lipids TC, LDL-c, TG and non-HDL-c (per 1% change in HbA1c, TC 0.101 mmol/l, 95% CI 0.050, 0.152; LDL-c 0.103 mmol/l, 95% CI 0.058, 0.148; TG 0.052 mmol/l, 95% CI 0.024, 0.081; and non-HDL-c 0.129 mmol/l, 95% CI 0.078, 0.180) but not HDL-c (-0.20 mmol/l, 95% CI -0.047, 0.007). The associations between HbA(1c) and any lipid outcome among those on dyslipidaemia medication were in the same direction, but attenuated compared with persons not on medication. CONCLUSIONS/INTERPRETATION: Change in HbA(1c) is significantly associated with change in fasting lipids, but dyslipidaemia medications may be required to optimise lipid and cardiovascular health.

Complications of obesity in children and adolescents.

The increasing prevalence and severity of obesity in children and adolescents has provided greater emphasis on the wide variety of comorbid conditions and complications that can be experienced as a consequence of obesity. These complications can occur both in the short term and in the long term. Some complications, earlier thought to be long-term issues, which would only occur in adulthood, have now been shown to occur in children and adolescents. These findings have raised concerns about the overall health experience of those who develop obesity early in life and have even raised questions about whether the obesity epidemic might shorten the life span of the current generation of children. In this paper, I will examine current knowledge regarding the different organ systems that may be impacted by childhood obesity.

The relationship between meal frequency and body mass index in black and white adolescent girls: more is less.

OBJECTIVE: To document meal frequency and its relationship to body mass index (BMI) in a longitudinal sample of black and white girls from ages 9-19 years. DESIGN: Ten-year longitudinal observational study. SUBJECTS: At baseline, 1209 Black girls (539 age nine years, 670 age 10 years) and 1,166 White girls (616 age nine years, 550 age 10 years) were enrolled in the National Heart, Lung and Blood Institute Growth and Health Study (NGHS). MEASUREMENTS: Three-day food diaries, measured height and weight and self-reported physical activity and television viewing were obtained at annual in-person visits. RESULTS: Over the course of the study, the percentage of girls eating 3+ meals on all 3 days was reduced by over half (15 vs 6%). Participants who ate 3+ meals on more days had lower BMI-for-age z-scores. Black girls, but not white girls, who ate 3+ meals on more days were less likely to meet criteria for overweight. CONCLUSION: Meal frequency was related to BMI and should be considered when developing guidelines to prevent childhood overweight.

Relation of heart rate to left ventricular dimensions in normotensive, normal-weight children, adolescents and adults.

BACKGROUND: The quantitative relation between body growth and changes in heart rate, and the relationship of heart rate to left ventricular (LV) dimensions, independent of the influence of body size, have been only marginally investigated. Accordingly, we designed this study to investigate the relation between heart rate, body size and LV dimensions in children, adolescents and adults over a broad age span. METHODS: Eight hundred and nineteen normotensive, multi-racial, normal-weight individuals (444 males, 375 females, aged 1-85 years) with normal LV systolic function were studied at echocardiography in three centers, using previously reported methods. The resting heart rate was measured on the M-mode echo-tracing or right after the echocardiogram with the subject still in the supine position. RESULTS: In children and adolescents (up to 17 years), the heart rate decreased with increasing body height (r = -0.51, p < 0.0001) and body weight (r = -0.42, p < 0.0001), in a similar manner in girls and boys. In adults, the heart rate was higher in women than in men, but it was not independently related to body size. The LV diastolic diameter was higher in males and decreased with increasing heart rate in children and adolescents (r = -0.45) as well as in adults (r = -0.25, both p < 0.0001). This relation was also independent of the effect of body size, sex and race. Similarly, the LV mass increased with decreasing heart rate in children and adolescents (r = -0.45), but the association was not confirmed after controlling for body size, sex and race. In adults, heart rate was inversely related to LV mass (r = -0.21, p < 0.0001), and this relation was also independent of body size, sex, race, age and blood pressure (p < 0.001). In women, the relation of heart rate to LV mass/height2.7 was less close than in men, due to the greater increase in LV mass with age. CONCLUSIONS: The heart rate has an inverse association with the LV chamber diameter and with the LV mass in children-adolescents and in adults. This relation is largely, but not uniquely, mediated by body proportions, especially during body growth.

Effects of race, cigarette smoking, and use of contraceptive medications on resting energy expenditure in young women.

The prevalence of obesity is higher in Black women than in White women (JAMA 1994;272:205-11; Arch Pediatr Adolesc Med 1995;149:1085-91). Although it has been shown that Black women have a lower resting energy expenditure (REE), factors affecting REE remain unclear. This 1996-1997 study in Cincinnati, Ohio, assessed racial differences in REE and their determinants in a biracial cohort of 152 healthy young women aged 18-21 years. Two indirect calorimetric measurements were obtained during two overnight hospital admissions 10-14 days apart. Body composition was measured by using dual-energy x-ray absorptiometry. Mean REE (adjusted for body composition, smoking, and contraceptive medication use) was significantly (p = 0.04) lower by 71 kcal/day in Black women (1,453 (standard error, 21) kcal/day) than in White women (1,524 (standard error, 19) kcal/day). Smoking was associated with a REE that was 68 kcal/day higher for both groups (p = 0.03). A trend (p = 0.07) toward increased REE (by 46 kcal/day) was found with contraceptive medication use. In conclusion, young Black women had a significantly lower REE than did White women. Cigarette smoking significantly increased REE. The apparent presence of a more parsimonious energy metabolism in Black women suggests that maintenance of energy homeostasis requires particular vigilance in this high-risk population.

Cardiovascular disease risk factors and atherosclerosis in children and adolescents.

As more is learned about the natural history of the development of atherosclerosis, it is clear that the process that results in morbidity and mortality in adults has its origins in childhood and adolescence. It is also clear that the traditional risk factors, such as hypertension and dyslipidemia, are important in the early stages of the process. It appears that the prevalence and severity of obesity are increasing in children and adolescents in the United States. This trend is associated with increasing blood pressure and the occurrence of type 2 diabetes mellitus in young individuals. These trends may result in increased cardiovascular morbidity and mortality as these overweight pediatric patients become obese adults. Intervention and prevention strategies should be directed at the pediatric population as a whole, as well as at higher-risk individuals. For the latter, it will be necessary to identify those at highest risk. Both nonpharmacologic and pharmacologic approaches may be necessary for treatment of pediatric patients with hyperlipidemia and hypertension. Studies are needed that evaluate the longer-term impact of intervention on cardiovascular risk factors in young patients.