Nutritional Status and Renal Function in Relation to Frailty among the Community-Dwelling Elderly Taiwanese Population.

OBJECTIVES: Frailty is a significant public health and clinical issue among the elder population. This study aimed to evaluate the nutritional status and renal function in relation to frailty among elderly Taiwanese. DESIGN: We administered community-based health surveys to the elder population in Chiayi County, Taiwan, from 2017 to 2019. MEASUREMENTS: We measured nutritional status (including serum albumin and total protein levels), renal function (including serum blood urea nitrogen, creatinine, urine protein, and urine creatinine levels), hand grip strength (GS) and calculated appendicular muscle mass (AMM). RESULTS: The study recruited 3739 participants (2139 women). Participants of both sexes with normal GS had higher serum albumin levels and lower urine protein/creatinine ratios (UPCRs). For the men with normal and weak GS, serum albumin levels were 4.15 ± 0.2 and 4.10 ± 0.2 g/dL (p < 0.01), and UPCRs were 123.1 ± 219.6 and 188.7 ± 366.2 (p < 0.001), respectively. GS was positively correlated with serum albumin and urine creatinine levels (r = 0.136 and 0.177, both p < 0.001). AMM was also positively correlated with serum albumin and urine creatinine levels (r = 0.078 and 0.091, both p < 0.001). In the multivariate regression model, for every 1 g/dL increase in serum albumin level, there was a 1.9 and 1.7-kg increase in GS for men and women (p < 0.05 and p < 0.01), respectively. The final model for predicting GS included age, albumin, BUN, and UPCR (urine creatinine for women) which presented a variance of 22.1% and 13.8%, respectively. CONCLUSION: Proper dietary nutritional intake and maintaining renal function are key elements for preventing frailty among elder population in Taiwan.

Rapid molecular diagnosis of the Gilbert's syndrome-associated exon 1 mutation within the UGT1A1 gene.

Gilbert's syndrome is suspected in patients with unconjugated hyperbilirubinemia caused by decreased activity of the UDP-glucuronosyltransferase 1A1 (UGT1A1) gene in the absence of abnormal liver function and hemolysis. The major genetic variants underlying Gilbert's syndrome are TATA-box repeats of the promoter region and exon 1 G211A of the coding region, particularly in Asians. The efficacy of DNA melting curve analysis, however, has not been established for the G211A mutation. For rapid and accurate molecular diagnosis of Gilbert's syndrome, DNA melting curve analysis was evaluated for its genotyping capability not only for TATA-box repeats of the UGT1A1 promoter, but also for G211A of UGT1A1 exon 1. TA repeats within the TATA-box sequence and the exon 1 G211A mutation of the UGT1A1 gene were analyzed by DNA melting curve analysis. To evaluate the assay reliability, direct sequencing or polyacrylamide gel electrophoresis was used as a comparative method. All homozygous and heterozygous polymorphisms of A(TA)7TAA within the TATA-box allele and of exon 1 G211A mutants of the UGT1A1 gene were successfully identified with DNA melting curve analysis. DNA melting curve analysis is, therefore, an effective molecular method for the rapid diagnosis of Gilbert's syndrome, as it detects not only TATA-box polymorphisms but also the exon 1 G211A mutation located within the UGT1A1 gene.

The trend of hypertension and its relationship to the weight status among Taiwanese young adolescents.

This study evaluates prevalence of hypertension in 1996 and 2006, and examines the relationship between hypertension and weight of Taiwanese young adolescents. Two cross-sectional surveys, administered in 1996 and 2006, to junior-high school in Taipei were included. Anthropometric and blood pressure were measured using standard methods, and structured questionnaire was used to collect personal history and lifestyle characteristics. Overweight and obesity are defined based on Taiwan's Department of Health criteria and bases pre-hypertension and hypertension on the 90th and 95th percentile distribution of blood pressure of the population of both surveys. The prevalence of pre-hypertension in Taiwan between 1996 and 2006 increased from 12.0 to 14.4% for boys and decreased from 9.5 to 9.4% for girls. Hypertension increased from 22.8-29.7% and 12.5-20.7% for both boys and girls, respectively. In 1996, compared with normal young adolescents, the risk of hypertension for overweight was 1.8 times higher for boys and 3.4 times for girls. However, the risk of hypertension for overweight in 2006 was 1.7 times higher for boys and 1.5 times higher for girls compared with normal. Every unit increment of body mass index and waist circumference was associated with 17-27% and 6-11% risk of hypertension in both genders in 1996, and was associated with 9-13% and 4% risk of hypertension among young adolescents in 2006, respectively. The prevalence of hypertension has increased significantly in young adolescents, especially for overweight. It is necessary to enrol young adolescents in weight management programs to prevent hypertension-related co-morbidities.

Combined effect of C-reactive protein gene SNP +2147 A/G and interleukin-6 receptor gene SNP rs2229238 C/T on anthropometric characteristics among school children in Taiwan.

OBJECTIVE: The purpose of this study was to explore the combined effect of the C-reactive protein (CRP) +2147 A/G (rs1205) and interleukin (IL)-6R rs2229238 C/T single-nucleotide polymorphisms (SNPs) on the anthropometric variables of school children in Taiwan. SUBJECTS AND DESIGN: Cross-sectional analyses were performed using the data from the Taipei Children Heart Study-II. After multi-stage sampling, we selected 430 boys and 463 girls with an average age of 13.1 years. We genotyped these individuals for the CRP +2147 A/G and IL-6R rs2229238 C/T SNPs using a TaqMan 5' nuclease assay. Anthropometric characteristics, which included body height, body weight (BW), body mass index (BMI), waist circumference (WC), hip circumference (HC), body fat percentage (BF), and waist circumference to height ratio (WHtR), were measured/calculated. RESULTS: When considering the CRP +2147 A/G polymorphism, GG genotype boys were heavier and had larger BMI, WC, HC, BF and WHtR than A allele carriers. The odds ratio (OR) of larger WHtR in GG genotype boys was 2.14 (95% CI: 1.09-4.21). For the IL-6R rs2229238 C/T polymorphism, T allele carrier girls had larger WC and WHtR than those carrying the CC genotype. The OR of a larger HC for T allele carrier boys was 2.33 (95% CI: 1.16-4.68). Boys with the GG genotype of CRP +2147 A/G and the CC genotype of IL-6R rs2229238 C/T had higher OR for BW, BMI, WC, HC, BF and WHtR than boys who were carriers of the A allele of CRP +2147 A/G and had the CC genotype of IL-6R rs2229238 C/T (OR range=3.86-8.04, all P<0.05). CONCLUSION: Boys who carry the GG genotype of CRP +2147 A/G and the CC genotype of IL-6R rs2229238 C/T have a greater risk of having abnormal BW, BMI, WC, HC, BF and WHtR and of developing obesity than individuals who do not have these genotypes.

Correlation of plasma leptin and adiponectin with insulin sensitivity and beta-cell function in children - the Taipei Children Heart Study.

To investigate the association between plasma leptin and adiponectin and insulin sensitivity in children, 580 school children (294 boys and 286 girls) with mean age of 13.3 years (12-16 years) were randomly selected from the Taipei Children Heart Study. Baseline measurements included body weight, body mass index (BMI), plasma glucose, insulin, proinsulin, leptin and adiponectin levels. Insulin resistance and beta-cell function were assessed using the method of homeostatic model, HOMA-IR and HOMA-beta, respectively. We found that girls had higher levels of plasma leptin, adiponectin and HOMA-beta than boys. There was no significant difference in HOMA-IR between boys and girls. Plasma leptin concentrations were positively correlated with body weight, BMI, insulin and proinsulin concentrations, HOMA-IR and HOMA-beta, whereas plasma adiponectin levels were inversely associated with body weight, BMI and proinsulin levels in both sexes. In girls, adiponectin concentrations were negatively correlated with insulin concentration and HOMA-IR. In multiple regression analyses, plasma leptin was more positively associated with insulin and proinsulin levels, HOMA-IR and HOMA-beta than was adiponectin in boys. This association persisted even after adjusting for body weight, BMI and pubertal status. In conclusion, plasma leptin was more strongly associated with insulin sensitivity and beta-cell function than was adiponectin among children, particularly in boys.

Prevalence of obesity in Taiwan.

In Taiwan, the prevalence and problem of obesity has increased significantly in recent decades and has became an important public health issue. In children (12-15 years), the prevalence of obesity (defined as body weight > 120% of mean body weight with age- and gender-specification) was 12.4%, 14.8% and 15.6% among boys and 10.1%, 11.1% and 12.9% among girls in 1980, 1986 and 1996 respectively. A survey of 1500 12-15-year-old children during 1995-1996 in Taipei city found that about 16.6% of boys and 11.1% of girls were obese, while an additional 11.6% of boys and 10.2% of girls were overweight. In adults, using the criteria defined by the Department of Health in Taiwan [overweight as (body mass index) BMI > or = 24 and obese as BMI > or = 27], the age-adjusted prevalence of obesity was 10.5% and 15.9% for men and 13.2% and 10.7% for women from 1993-1996 to 2000-2001. From these data, we found that the prevalence of obesity in Taiwan has increased steadily from 1980 to 2000 especially in children and in men.

Plasma C-reactive protein concentrations in relation to 5-year body weight change among children: the Taipei Children Heart Study.

OBJECTIVE: C-reactive protein (CRP), a nonspecific inflammatory marker, may be associated with the development of cardiovascular disease (CVD) among adults. The purpose of this study is to evaluate the relation between plasma CRP levels and 5-y body weight and body mass index (BMI) change among school children in Taiwan. METHOD: In 1995, we conducted an epidemiological survey to evaluate the anthropometric characteristics and CVD risk factors among 1500, aged 12-15 y, school children in Taipei. We measured plasma high sensitivity CRP levels using nephelometric method. In 2000, we followed these children to evaluate their changes in body height, weight and BMI during 5 y. RESULTS: In general, boys were taller, heavier and had higher BMI than girls at the baseline (1995) and at the 5-y follow-up (2000). Baseline plasma CRP levels were positively correlated with body weight and BMI in both 1995 and 2000. However, plasma CRP levels were negatively correlated with 5-y BMI change in both genders. We further divided the children into three subgroups based on their baseline CRP levels (nondetected, 0.188-1.00 and >1.0 mg/dl). Children in the higher plasma CRP levels (>1.0 mg/dl) were heavier and had higher BMI (both in 1995 and 2000) than those children with nondetected CRP levels. However, children with higher CRP subgroup had a lower 5-y increasing of BMI and there was even a decrease of BMI levels among the higher CRP girls. CONCLUSION: From this prospective study, we found that baseline plasma CRP levels were positively correlated with the baseline and the 5-y follow-up body weight and BMI in both genders. However, plasma CRP levels may not be a good predictor of 5-y body weight and BMI changes among children in Taiwan.

Familial resemblance of adiposity-related parameters: results from a health check-up population in Taiwan.

The mechanisms of obesity is still unclear, however, genetic and environmental factors are two major possible causes of obesity. The purpose of this study was to assess the degree of familial resemblance of different obesity-related parameters in a health check-up population in Taiwan. We measured body mass index (BMI), waist-to-hip ratio (WHR) and percentage of body fat (BFAT) anthropometrics in 1724 members of 431 families participating in the MJ Health Screening program. Each family contributed four members, i.e. father, mother, son, and daughter. All the participants were free from coronary heart disease, hypertension, diabetes, dyslipidemia, and generally in good health. The degree of familial aggregation was measured by heritability that was calculated based on age-adjusted familial (parent-offspring, sibling, spouse) correlations. The maximal heritability estimates were 39, 30 and 35% for BMI, WHR and BFAT, respectively. For WHR, the correlation between spouses was not significant and the heritability appears to be predominantly due to genetic causes. Furthermore, for BMI and BFAT, the spouse correlations were 0.08 and 0.11, respectively. The heritabilities for BMI and BFAT were mostly explained by genetic factors and familial environmental factors such as dietary habits or physical activity. The familial resemblance of various obesity-related parameters was moderate in a health check-up population in Taiwan. While the heritability for WHR appears to be mainly due to genetic factors, the familial resemblance for BMI and percentage of BFAT may involve both genetic and familial environmental factors.

Determinants and distributions of plasma total homocysteine concentrations among school children in Taiwan.

BACKGROUND: Plasma total homocysteine (tHcy) level is an independent risk factor for cardiovascular disease (CVD) even among children. The purpose of this study is to evaluate the determinants and distributions of plasma tHcy levels and the relationship between plasma tHcy, folate and vitamin B12 levels among school children in Taipei. METHODS: After multi-stage sampling, we randomly selected 1234 school children (609 boys and 625 girls) with the mean age of 13 years (from 12 to 15 years) in this study. Fasting plasma tHcy levels were measured using an ABBOTT IMx analyzer (Axis Biochemicals ASA, Oslo, Norway). Plasma folate and vitamin B12 levels were measured by ACS:180 automated chemiluminescence analyzer (Bayer, Tarrytown, NY, USA). RESULTS: The distribution of plasma tHcy levels were skewed to the right with the mean values of 10.50 and 8.95 micromol/l and medians of 9.67 and 8.474 micromol/l for boys and girls, respectively. Plasma tHcy concentrations were lower in younger children and progressively increased with increasing age. Boys had significantly higher plasma tHcy levels than girls (10.50 +/- 4.134 vs. 8.95 +/- 2.61 micromol/l, p < 0.01) and lower plasma folate levels (6.05 +/- 2.85 vs. 6.39 +/- 2.58 nmol/l, p < 0.01), and vitamin B12 levels (444.8 +/- 158.4 vs. 495.0 +/- 181.5 pmol/l, p < 0.001). Plasma tHcy levels were significantly positively associated with anthropometric measures in boys; but these characteristics attenuated and became insignificant after adjusting for other potential confounders in girls. Plasma tHcy levels were negatively associated with plasma folate and vitamin B12 levels even after adjusting for BMI and other potential confounders in both genders. CONCLUSIONS: From this study, the distributions of tHcy levels were skewed to the right and the boys had higher plasma tHcy levels than girls. Plasma tHcy levels were significantly positively associated with BMI among boys. Further studies are needed to evaluate the relationship between tHcy and CVD risk factors among children for the better prevention of heart disease in early life.

Assessment of questionnaire validity for measuring total fat intake using plasma lipid levels as criteria.

The validation of dietary total fat measurements has been elusive because no specific biomarker exists. In metabolic studies with controlled diets, plasma fasting triglyceride levels are reduced with higher fat intake and can thus serve as an "alloyed gold" standard. Participants in this cross-sectional analysis were 269 men aged 47-83 years from the Health Professionals Follow-up Study who completed a semiquantitative food frequency questionnaire and provided fasting blood specimens in 1994. In a multiple regression analysis adjusted for age; smoking; alcohol consumption; physical activity; body mass index; and intakes of protein, dietary fiber, and total energy, total fat intake was inversely associated with fasting triglycerides (for a fat increase of 1% of energy, triglyceride levels were lower by 2.5% (95% confidence interval: -3.7 to -1.3%, p = 0.0002)). For reported fat intakes of 20% or less of energy, the geometric mean fasting triglyceride level was 179, and for more than 40% of energy, it was 102 mg/dl. In addition, as predicted by metabolic studies, the inverse association between dietary fat and fasting triglyceride level was much stronger among overweight men than among men with a BMI of less than 25. These data provide additional evidence that informative measurements of dietary fat can be obtained by carefully constructed food frequency questionnaires.

Prevalence and clustering of cardiovascular risk factors among healthy adults in a Chinese population: the MJ Health Screening Center Study in Taiwan.

OBJECTIVE: To gain insight into the prevalence and clustering of multiple cardiovascular risk factors in a healthy Chinese adult population in Taiwan. DESIGN: A cross-sectional study was carried out in 1996. SUBJECTS: A total of 46,603 subjects (23,485 men and 23,118 women) who were aged 20--59 y and attended a private health screening center for health examination of their own volition. MEASUREMENTS: Multiple cardiovascular risk factors including cigarette smoking, overweight (23 kg/m(2)< or =body mass index (BMI)<25 kg/m(2)) and obesity (BMI> or =25 kg/m(2)), lipid disorder (a ratio of total cholesterol level to the level of high density lipoprotein cholesterol>5 or use of lipid-lowering drugs), hypertension (systolic blood pressure> or =140 mmHg or diastolic blood pressure> or =90 mmHg or use of anti-hypertensive medications), and diabetes mellitus (fasting serum plasma glucose level> or =126 mg/dl or use of anti-diabetic medications) were determined. RESULTS: In comparison to women, men had a higher prevalence of current smoking (42.1 vs 5.6%), overweight (25.1 vs 17.1%) and obesity (33.1 vs 21.5%), lipid disorder (45.1 vs 19.6%), hypertension (17.4 vs 13.2%), as well as diabetes mellitus (4.1 vs 3.4%). The prevalence of men or women having two or more of the cardiovascular risk factors of interest was 54.3 and 21.7%, respectively. With advancing age, the prevalence of risk factors became greater for both genders. More importantly, the clustering of risk factors increased monotonically with increasing BMI levels for men and women. CONCLUSIONS: The prevalence and clustering of cardiovascular risk factors are commonplace in this healthy Chinese adult population. Considering the significant association between clustering of risk factors under study and BMI levels, this study gives an indication that population-based multifactorial interventions may work out favorably for specific groups.

Plasma insulin, leptin, and soluble TNF receptors levels in relation to obesity-related atherogenic and thrombogenic cardiovascular disease risk factors among men.

Obesity is related to cardiovascular disease (CVD) morbidity and mortality, however, the mechanisms for the development of obesity-induced CVD risk remain unclear. Hyperinsulinemia and insulin resistance are considered key components in the metabolic cardiovascular syndrome and as independent risk factors for CVD. Plasma leptin and tumor necrosis factor-alpha (TNF-alpha), two adipocyte products, are also proposed to be associated with the development of CVD risk. The purpose of this study is to evaluate the association of plasma leptin, soluble TNF receptors (sTNF-R), and insulin levels as possible mediators of the effect of obesity on atherogenic and thrombogenic CVD risk factors among men. From the Health Professionals Follow-up Study (HPFS), we selected 268 men, aged 47--83 years, who were free of CVD, diabetes, and cancer (except non-melanoma skin cancer), and who had provided a fasting blood sample in 1994. We measured plasma insulin and leptin levels by radioimmunoassay and sTNF-R levels by ELISA. Men in the highest quintile of body mass index (BMI, mean=30.5 kg/m(2)) were less physically active and had a more adverse cardiovascular lipid and homeostatic profile, as indicated by levels of insulin, triglyceride (TG), tissue plasminogen activator (t-PA) antigen levels, and apolipoprotein A1 (Apo-A1). In a multivariate regression model controlling for age, smoking, alcohol intake, physical activity and diet, BMI was inversely associated with HDL-cholesterol (HDL-C) and Apo-A1 and positively associated with TG, Apo-B and t-PA antigen levels. The associations between BMI and these CVD risk factors were only slightly changed after adjusting for leptin and/or sTNF-R; but were substantially attenuated after controlling for insulin levels. These data suggest that the association between obesity and biological predictors of CVD may be mediated through changes in plasma insulin, rather than leptin or sTNF-R levels. However, plasma leptin may still play a role in CVD through independent effects on lipid metabolism.

Prevalence and trends of obesity among school children in Taiwan--the Taipei Children Heart Study.

BACKGROUND: In Taiwan, the availability of a high-fat and high-energy diet has steadily risen over the past 30 y, while people have become increasingly sedentary. This lifestyle of poor diet and little physical activity has caused the prevalence of obesity to increase among adults and children. Obesity and associated chronic disease risk factors are becoming important public health issues. The purpose of this study is to evaluate the prevalence and secular trends of being overweight and obese among school children in Taiwan. METHODS: We conducted a cross-sectional survey among junior high school students in Taipei in 1994 to ascertain a representative distribution of demographic, lifestyle and biochemical characteristics, including several cardiovascular disease risk factors. After multistage sampling of 85 junior high schools in Taipei, we randomly selected 1500 children for this survey. We defined being overweight and obese based on ideal body weight (IBW) criteria. Children are considered to be overweight if their body weight is 110-120% of IBW, and obese if their body weight is greater than 120% of IBW within age- and gender-specific strata. RESULTS: In general, obese children have higher blood pressure, plasma glucose and triglyceride levels and lower high-density-lipoprotein cholesterol levels than normal-weight children. From 1980 to 1994, the mean value of body weight increased significantly over increases in body height (especially among boys). Although the percentage of overweight children remained steady from 1980 to 1994 in both genders, the prevalence and trends of obesity increased significantly, especially among boys and older girls. CONCLUSION: From this survey we find that in Taiwan from 1980 to 1994 body weight increased dramatically over body height among school children. The prevalence of obesity also increased significantly, especially among boys, while the percentage of overweight children did not vary. Overall, this study indicates that obesity and the adverse effects of being over the ideal body weight is no longer just a problem of Western countries.

Plasma leptin concentrations and four-year weight gain among US men.

OBJECTIVE: Leptin, a primarily adipose tissue-derived protein product of the obesity (ob) gene, is an important regulator of energy metabolism. The strong association between body fat mass and elevated circulating leptin levels in humans suggests that leptin resistance, rather than leptin production, may contribute to the development of obesity and associated disorders. The purpose of this study is to evaluate the relationship between circulating plasma leptin levels and regulation of body weight over time among US men. DESIGN: Four-year prospective study. SUBJECTS: A total of 247 men from the Health Professionals Follow-up Study, who at baseline (1994), were 47-64 y of age, were free of cardiovascular diseases, diabetes mellitus and malignant neoplasmas, and completed a detailed lifestyle questionnaire. In addition, all participants completed a follow-up questionnaire in 1998. MEASUREMENTS: Baseline plasma leptin levels and 4-y weight change. RESULTS: At the start of follow-up, men in the highest quintile for plasma leptin (mean=12.1 ng/ml) weighed more, were less physically active, and had higher circulating insulin levels than men in the lowest quintile (mean=2.7 ng/ml). After adjustments for baseline age, weight, height, smoking status, alcohol intake, and physical activity, each 10 ng/ml increase in plasma leptin concentration was associated with a 1.68 kg (95% CI 0.14-3.18 kg) weight gain over the 4-y follow-up period. The observed association between leptin level and weight gain was limited to men with a baseline body mass index (BMI) of > or =25 kg/m2, in whom a 10 ng/ml higher baseline leptin was associated with a 2.45 kg (95% CI 0.73-4.18-kg) weight gain. Further adjustments for baseline total energy intake, plasma insulin and soluble tumor necrosis factor receptors levels did not appreciably alter these results. Plasma insulin level was not independently associated with subsequent weight gain. CONCLUSION: These results suggest that elevated plasma leptin concentrations among overweight men may be a marker of leptin resistance and subsequent weight gain.

Dietary and lifestyle factors in relation to plasma leptin concentrations among normal weight and overweight men.

OBJECTIVE: Leptin, the product of the obesity (ob) gene, is a multi-functional polypeptide that is important in energy metabolism, which is strongly correlated with body fat mass and body mass index (BMI). In a recent prospective study, we found that leptin was positively associated with 4 y weight gain among overweight and obese men. This suggests that leptin resistance, marked by hyperleptinemia among obese subjects, may be an important marker for weight gain. The purpose of this study is to evaluate whether modifiable dietary and lifestyle factors are associated with plasma leptin concentrations among US men. METHODS: We included 268 men aged 47--83 y (who were free of cardiovascular disease, diabetes mellitus and cancer, except nonmelanoma skin cancer) from the ongoing Health Professionals Follow-up Study. These subjects completed a detailed dietary and lifestyle questionnaire (including cigarette smoking, alcohol drinking and physical activity) and provided a fasting venous blood sample in 1994. All blood samples were stored in a deep freeze (-70 degrees C) for 4--5 y before being analyzed. Plasma leptin concentrations were measured by radioimmunoassay. RESULTS: Men in the highest quintile of plasma leptin (mean=14.4 ng/ml) weighed more, were less physically active, and had higher total and saturated fat and cholesterol intake than men in the lowest quintile (mean=3.0 ng/ml). Physical activity and current smoking were inversely associated with plasma leptin concentrations (P<0.001). A 20 MET difference in physical activity per week (equivalent to approximately 3 h of jogging) was associated with 0.38--0.58 ng/ml lower plasma leptin concentrations for normal weight and overweight men after adjusting for total energy and fat intake, BMI and other confounding variables. Total fat and monounsaturated fat intakes were positively associated with plasma leptin concentrations even after adjusting for BMI and other confounding variables; however, this association was limited to men of normal weight (BMI<25 kg/m(2)). CONCLUSION: These data suggest that physical activity may be a significant determinant of plasma leptin concentrations in men. Increasing physical activity is associated with lower plasma leptin concentrations even after adjusting for BMI. Physical activity may lower leptin concentrations not only due to decreased body fat mass, but potentially through an increase in leptin sensitivity. International Journal of Obesity (2001) 25, 106-114

Obesity, leptin and blood pressure among children in Taiwan: the Taipei Children's Heart Study.

BACKGROUND: Obesity is associated with the occurrence of hypertension; however, the mechanisms of obesity-induced high blood pressure (BP) remain unclear. Leptin, the obese (ob) gene product, is associated with the occurrence of obesity and related disorders in humans. The purpose of this study was to evaluate the association between plasma leptin and BP among children. METHODS: After multistage sampling, we randomly selected 1265 children (618 boys and 647 girls) with a mean age of 13.3 years (12 to 16 years old) in this cross-sectional survey. Obesity measurements included body mass index (BMI) and waist-to-hip circumference ratio (WHR). Plasma leptin levels were measured by radioimmunoassay. RESULTS: The mean and median plasma leptin levels were 4.1 and 2.4 ng/mL among boys and 10.1 and 8.8 ng/mL among girls. Children in the highest quintile of leptin level (mean, 11.1 and 19.7 ng/mL for boys and girls, respectively) had higher body weight, BMI, WHR, BP, and insulin levels than children in the lowest quintile (mean, 1.1 and 3.9 ng/mL for boys and girls, respectively). Boys had a higher BMI, WHR, and BP levels, yet had lower leptin levels than girls. In both genders, BMI and plasma leptin levels were significantly positively correlated with BP. In multivariate regression analyses, plasma leptin levels were positively associated with BP; however, this association became insignificant among girls and even inversely associated with systolic BP among boys after adjusting for BMI. CONCLUSIONS: Obesity is positively associated with BP among school children in Taiwan; however, the role of plasma leptin on the development of obesity-related hypertension is still controversial among school children.

Relationship between plasma leptin levels and lipid profiles among school children in Taiwan--the Taipei Children Heart Study.

Leptin, an adipose tissue-derived of gene product, is important in energy metabolism. However, the role of leptin in the metabolism of lipids is still not clear in humans. The purpose of this study was to evaluate the association of plasma leptin concentrations and lipid profiles among school children in Taiwan. After multistage sampling of 85 junior high schools in Taipei, we randomly selected 1264 children (617 boys and 647 girls) aged 12-16 years for this study. We measured the anthropometric variables, lifestyle factors and biochemical parameters among these children. Anthropometric measurements included body height (BH) and weight (BW) and we calculated body mass index (BMI) as the ratio of the BW to the square of the BH, expressed in kg/m2. Plasma leptin levels were measured by radioimmunoassay. We also measured lipid profiles including serum total cholesterol (CHOL), triglyceride (TG), high density lipoprotein-cholesterol (HDL-C), apolipoprotein-A1 (Apo-A1), apolipoprotein-B (Apo-B), and lipoprotein(a) (Lp(a)) levels, and calculated low density lipoprotein-cholesterol (LDL-C) levels and CHOL to HDL-C ratio (TCHR). Girls had higher leptin, CHOL, TG, HDL-C, (LDL-C), Apo-A1, Apo-B, and Lp(a) levels and lower BMI than boys did. Plasma leptin concentrations were significantly positively correlated with TG, LDL-C, and Apo-B, but negatively with HDL-C and Apo-A1 in both the genders. Children with higher plasma leptin levels (>75th percentiles) have significantly higher TG, HDL-C, LDL-C, TCHR, and Apo-B than those with relatively lower leptin levels. In multivariate regression analyses, the association between plasma leptin level and lipid profiles (such as CHOL, TG, and Apo-B) were still significant (p < 0.05) even after adjusting for BMI among boys. However, this association became attenuated and insignificant among girls. Finally, in the model that included the standard covariates, plasma leptin was the most predictive of CHOL, TG and Apo-B levels among those school children in Taiwan. Our results suggest that plasma leptin and BMI were independently associated with the lipids and lipoprotein profiles among Taiwanese Children. In both genders, children in the top 25% of the leptin distribution have more adverse lipid and lipoprotein profiles.

Leisure-time physical activity, television watching, and plasma biomarkers of obesity and cardiovascular disease risk.

The benefits of physical activity in reducing cardiovascular disease (CVD) are thought to be mediated through changes in blood lipids, insulin sensitivity, and thrombogenic factors. Few studies have addressed the effects of both long-term physical activity and inactivity on these factors. The authors assessed associations between long-term leisure-time physical activity, television watching, and biomarkers of CVD risk among 468 healthy male health professionals. Prior to blood collection in 1993-1994, physical activity and television watching were assessed biennially from 1986 to 1994 by a questionnaire. Physical activity was expressed as metabolic equivalents-hours per week. Multivariate linear regression analyses showed that metabolic equivalents-hours in 1994 were significantly associated with high density lipoprotein cholesterol (HDL cholesterol) (positively) and with leptin and C-peptide (inversely). The average number of hours of television watching assessed in 1994 was significantly positively associated with low density lipoprotein cholesterol and significantly inversely associated with HDL cholesterol and apolipoprotein A1. Average hours of television watching per week assessed in 1988-1994 was positively associated with leptin levels (p < 0.01). The associations of television watching and vigorous activity with leptin and HDL cholesterol were independent of each other. In conclusion, physical activity and television watching were significantly associated with several biochemical markers of obesity and CVD risk.

Plasma leptin concentrations and obesity in relation to insulin resistance syndrome components among school children in Taiwan--The Taipei Children Heart Study.

OBJECTIVE: Leptin, an adipose tissue-derived product of the obesity (OB) gene, is an important regulator of energy metabolism and may be associated with the occurrence of insulin resistance and diabetes in humans. The purpose of this study was to evaluate the association of plasma leptin concentration with obesity and the components of insulin resistance syndrome (IRS) among school children in Taiwan. METHODS: After multistage sampling of 85 junior high schools in Taipei, we randomly selected 1,264 children (617 boys and 647 girls) aged 12-16y. Obesity measurements included body mass index (BMI) and waist-to-hip circumference ratio (WHR). We calculated an IRS summary score for each individual by adding the quartile ranks from the distribution of systolic blood pressure (BP), serum triglyceride (TG), HDL-cholesterol (inverse), and insulin levels. RESULTS: Boys had a higher BMI and WHR, BP and IRS score and lower leptin, insulin, TG and HDL-C levels than girls. BMI, WHR and plasma leptin levels were significantly associated with the IRS summary score and each of its components in both genders. Children with higher plasma leptin levels (> 75th percentiles) have significantly higher BP, TG, insulin levels and IRS score than children with low leptin levels. The associations between plasma leptin level and the IRS components and score were still significant after adjusting for BMI in boys, but less so in girls. In both genders, after adjusting for WHR, plasma leptin levels were still significantly associated with the IRS components and summary score (P< 0.001). The final model that included the standard covariates, BMI and leptin, but not WHR, was the most predictive of the IRS summary score among school children. CONCLUSIONS: Insulin resistance syndrome in childhood, characterized by high blood pressure, dyslipidemia, and hyperinsulinemia, may be an early marker of cardiovascular risk. From the present BMI and leptin in combination are the most predictive markers of insulin resistance syndrome among school children in Taiwan.

Glycemic status and soluble tumor necrosis factor receptor levels in relation to plasma leptin concentrations among normal weight and overweight US men.

OBJECTIVE: Leptin, an adipocyte-derived protein product of the obesity (ob) gene, is a multifunctional polypeptide associated with the development of obesity-related disorders in humans. There is considerable inter-individual variation in plasma leptin even among subjects with comparable obesity levels, which suggests that factors other than adipose mass may be involved in the regulation of leptin expression and/or production. The purpose of this study was to evaluate the potential role of glycemic status and adipose-derived cytokines in regulating plasma leptin levels among normal and overweight men. DESIGN: Cross-sectional study. SUBJECTS AND MEASUREMENTS: We measured plasma leptin, insulin, c-peptide and plasma soluble tumor necrosis factor receptor (sTNF-R) concentrations in 178 men. The subjects were selected from the Health Professionals Follow-up Study (HPFS), and aged 47-64 y in 1994, were free of cardiovascular disease, diabetes mellitus, malignant neoplasms, and had provided a fasting blood sample and a detailed lifestyle questionnaire. RESULTS: Men in the highest quintile of plasma leptin (mean = 12.7 ng/ml) weighed more, were less physically active and had higher circulating insulin, c-peptide, sTNF-R1 and sTNF-R2 concentrations than men in the lowest quintile (mean = 2.8 ng/ml). We found a significant correlation between plasma insulin, c-peptide, glycosylated hemoglobin (HbA1c), and sTNF-R1 on leptin concentrations (with Spearman correlation coefficients ranging from 0.17 to 0.48 and all P < 0.05). Only HbA1c and sTNF-R1 were independently and positively associated with plasma leptin after further adjusting for body mass index and other metabolic parameters of interest. Interestingly, these observed associations were limited to men with a BMI > or = 25 kg/m2. CONCLUSION: Our results suggest that glucose homeostasis and the activity of the TNF system may modulate leptin secretion and production among overweight men. Glucose homeostasis and TNF-alpha is important in metabolic disorders related to hyperleptinemia.