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.

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.

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.

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 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 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.

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.

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.

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

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.

Relationship between single voided urine protein/creatinine ratio and 24-hour urine protein excretion rate among children and adolescents in Taiwan

BACKGROUND

As there have been few studies conducted on children or adolescents, the purpose of this study was evaluate the relationship between single voided urine protein/creatinine (Up/Ucr) ratio and 24-hour urine protein excretion rate (PER), especially among children and adolescents in Taiwan.

METHODS

After multistage random sampling, we collected 1,072 fasting single voided urine samples and 125 24-hour urine samples from seven- to 18-year-old students in Taiwan. We calculated the Up/Ucr of single voided urine samples and the 24-hour PER in urine.

RESULTS

The mean value and the 95th percentile of the fasting single voided urine Up/Ucr ratio were 0.118 and 0.235, respectively. The mean value and the 95th percentile of the 24-hour PER were 3.61 and 5.66 mg/h/m2, respectively. There was no significant difference in Up/Ucr ratio between boys and girls. Up/Ucr ratio decreased significantly as age increased. The fasting single voided Up/Ucr ratio was highly correlated with 24-hour PER, with r2 = 0.95 (p < 0.001).

CONCLUSIONS

Fasting single voided Up/Ucr ratio is a good marker of 24-hour PER. It is also a simple, easy, convenient and speedy method to measure Up excretion. The single voided Up/Ucr ratio may also serve as a reference for the clinical diagnosis of Up excretion among normal subjects.

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.

Relationship between hyperuricemia and other cardiovascular disease risk factors among adult males in Taiwan

Hyperuricemia is associated with cardiovascular disease risk factors such as obesity, impaired glucose tolerance, hypertension, and hyperlipidemia. However, this relationship between serum uric acid (SUA) concentrations and cardiovascular disease (CVD) is a controversial one, especially among males. The purpose of this study is to evaluate the association between SUA concentrations and other CVD risk factors among adult males in Taiwan. After multi-stage sampling procedures, we randomly selected 1743 Taiwanese males with a mean age of 35 years (from 22 to 54) in this study. Anthropometric, blood pressure and biochemical variables, including serum uric acid, glucose, total cholesterol and triglyceride concentrations, were measured. Among the study population, the mean SUA concentration was 6.5 +/-1.5 mg/dl. There were 290 (16.6%) subjects with SUA concentrations > or = 8.0 mg/dl (defined as hyperuricemia). Compared to normouricemic subjects, hyperuricemic subjects had significantly greater age-adjusted body weight (75.3 vs. 69.2 kg, p < 0.001), body mass index (BMI, 25.5 vs. 23.6 kg/m2, p < 0.001), higher blood pressure (BP, 120.2 vs. 115.2 mmHg for systolic BP and 78.5 vs. 75.3 mmHg for diastolic BP, both p < 0.001) and blood lipid concentrations (193.8 vs. 182.1 mg/dl for total cholesterol and 123.7 vs. 94.4 mg/dl for triglycerides, both p < 0.001). SUA concentration was positively correlated with body weight, BMI, BP and serum lipid concentrations (all p < 0.001). In multivariate regression analyses, after adjusting for potential confounders, SUA concentration was significantly positively associated with diastolic BP, serum total cholesterol and triglyceride concentrations. An increase of 1 mg/dl of SUA was associated with a 2.1 mg/dl elevation in serum total cholesterol (p < 0.001) and a 5.4 mg/dl increase in triglyceride (p < 0.001). From this study, we found that hyperuricemia in subjects is associated with being overweight, and having high blood pressure and hyperlipidemia. There is a significantly positive association between SUA concentration and other CVD risk factors among adult males in Taiwan.

Lipoprotein profiles, not anthropometric measures, correlate with serum lipoprotein(a) values in children: the Taipei children heart study

OBJECTIVE

Plasma lipoprotein(a) [Lp(a)] is a risk factor for cardiovascular disease. The purpose of this study is to evaluate the correlation of anthropometric measures, lipids and lipoprotein profiles and serum Lp(a) values among children in Taiwan. We will attempt to find parameters that will be able to predict Lp(a) levels in children.

DESIGN AND METHODS

After a probability-proportional-to size, multi-stages sampling procedure, we randomly sampled 1500 schoolchildren from 10 schools in Taipei city. Anthropometric measures including body weight, body height, waist and hip circumference and skinfolds were measured. We used standard methods to measure serum total cholesterol (CHOL), triglycerides (TG), high density lipoprotein-cholesterol (HDL-C), apolipoprotein A1 and B (ApoA1 and ApoB) and Lp(a) levels. We also calculated low density lipoprotein-cholesterol (LDL-C) and CHOL HDL-C ratio (TCHR) by formula.

RESULTS

We sampled 1283 children (635 boys and 648 girls) with a mean age of 13.3 years (from 12 to 16 years) in this study. The mean and medium serum Lp(a) levels were 16.8 and 8.8 mg/dl among boys and 20.8 and 11.9 mg/dl among girls. Children in the highest quintile of Lp(a) (mean = 49.6 and 58.6 mg/dl for boys and girls, respectively) had higher CHOL, LDL-C, ApoB levels and TCHR than children in the lowest quintile (mean = 3.1 and 3.7 mg/dl for boys and girls, respectively). Lipids and lipoprotein profiles, such as CHOL, LDL-C, Apo-B and TCHR were positively correlated with Lp(a) levels in both genders. Furthermore, the children with Lp(a) levels greater than or equal to 30 mg/dl had higher CHOL, LDL-C and Apo-B levels when compared to children with Lp(a) levels less than 30 mg/dl. After adjusting for age, cigarette smoking, alcohol drinking, puberty development and heart rates, LDL-C and ApoB levels were significantly positively associated with Lp(a) levels while ApoA1 was negatively associated among boys. Among girls, only Apo-B was significantly positively associated with Lp(a) and TG was negatively associated with Lp(a) levels. Most importantly, none of the anthropometric measures were significantly correlated with Lp(a) levels.

CONCLUSIONS

From this study, we found that lipids and lipoproteins profiles, rather than degree of adiposity as reflected by anthropometric measures, are significantly associated with serum Lp(a) levels among school children.

Reappraisal of the relation between blood lead concentration and blood pressure among the general population in Taiwan

OBJECTIVES

The relation between blood lead concentration (PbB) and blood pressure was examined in a Taiwan nationwide population survey of PbB from July 1993 to June 1994.

METHODS

After multistage sampling procedures, 2800 subjects (1471 males and 1329 females) with a mean (range) age of 44 (15-85) years were enrolled in this study. Anthropometric, blood pressure, and lifestyle factors were measured during household visits. The PbB was measured with a flameless atomic absorption spectrophotometer and all specimens were analysed in triplicate.

RESULTS

The mean (range) PbB among all study subjects was 6.5 (0.1-69.1) micrograms/dl; among males it was 7.3 (0.1-69.1) micrograms/dl and among females 5.7 (0.1-40.1) micrograms/dl). The mean (range) systolic blood pressure among all subjects was 123 (80-210) mm Hg, among males it was 127 (80-200) mm Hg and among females 119 (80-210) mm Hg. The diastolic blood pressure among all subjects was 78 (40-150) mm Hg; among males it was 80 (40-130) mm Hg; and among females 75 (40-150) mm Hg. Age, body height, body weight, and body mass index (BMI) were significantly correlated with systolic blood pressure or diastolic blood pressure in both sexes. The PbB (or the natural logarithmic transformed PbB) was not significantly correlated with blood pressure among males or females. After adjustment for the potential confounders of age, age2, BMI, milk intake, alcohol consumption, and cigarette smoking, systolic blood pressure was significantly associated with PbB among males with a regression coefficient (beta) of 0.185 (p = 0.015). No significant association between PbB and blood pressure was found among females.

CONCLUSIONS

From this study, only a weak association between systolic blood pressure and PbB was found among males. There was no strong evidence that PbB was a good predictor of blood pressure. However, the possibility that long term high body lead burden could cause high blood pressure could not be ruled out on the basis of this survey.

Risk factors for high blood lead levels among the general population in Taiwan

PURPOSE

Environmental and occupational lead pollution is a common problem in both developing and industrialized countries. The purpose of this study is to evaluate the risk factors for high blood lead levels among the general population in Taiwan.

METHODS

After multi-stage sampling, we randomly selected 2803 subjects (1471 males and 1332 females) for this study. Univariate and multivariate logistic regression analyses were conducted to evaluate the risk of high blood lead. To control for differences in age and gender, all analyses were with age-adjusted and gender-stratified.

RESULTS

Among males, the mean age is 46 years (15 to 85 years), mean and median blood lead levels is 7.3 and 6.3 microg/dl, respectively. Among females, the mean age is 43 years (15 to 84 years), mean and median blood lead level is 5.7 and 4.8 microg/dl, respectively. Among males, the history of herbal drug use, drinking water from well or spring sources, and occupational lead exposure are significantly different between relatively high and normal blood lead level subjects. The history of occupational lead exposure, history of herbal drug use, and well or spring sources of drinking water are the major risk factors for high blood lead with odds ratio of 4.62 (95% CI: 2.82-7.55), 3.09 (95% CI: 1.60-5.97), 2.06 (95% CI: 1.13-3.76), and 2.37 (95% CI: 1.39-4.04), respectively. Among females, these characteristics remain important except the sources of drinking water. The history of herbal drug use and occupational lead exposure become the major risk factors for high blood lead with odds ratio of 2.94 (95% CI: 1.26-6.88) and 7.72 (95% CI: 3.51-16.99), respectively. In multivariate logistic regression analyses, we find that the risk factors for high blood lead in both genders include a history of herbal drug use and occupational lead exposure. Among males, the drinking water sources and factories in the neighboring areas are also significant factors for high blood lead.

CONCLUSIONS

For the goal of reducing prevalence of high blood lead by the year 2000, the improvement and monitoring of the working environment, the careful attention to herbal drug use and the lead-free drinking water sources should be executed as thoroughly as possible to reduce the probability of lead pollution.

Clustering of cardiovascular disease risk factors among obese schoolchildren: the Taipei Children Heart Study

BACKGROUND

Childhood obesity increases the risk of obesity in adulthood and is associated with cardiovascular disease (CVD) risk factors such as hypertension, diabetes mellitus, and dyslipidemia.

OBJECTIVE

We evaluated the clustering of CVD risk factors among obese schoolchildren in Taiwan.

DESIGN

After multistage sampling of 85 junior high schools in Taipei, we randomly selected 1366 children (681 boys and 685 girls) aged 13.3 y (range: 12-16 y). Anthropometric, blood pressure (BP), and biochemical CVD risk factors (including blood glucose, lipid, and lipoprotein concentrations) were measured.

RESULTS

Boys had a higher body mass index, systolic BP, and glucose concentrations than girls and girls had higher lipid and lipoprotein concentrations than boys. After adjustment for age, obese boys had a significantly higher BP, ratio of total to HDL cholesterol, and glucose, cholesterol, triacylglycerol, HDL cholesterol, LDL cholesterol, apolipoprotein A-I, and apolipoprotein B concentrations than nonobese boys. BP, HDL cholesterol, LDL cholesterol, and ratio of total to HDL cholesterol were significantly different between nonobese and obese girls. Approximately 70% of obese boys had one and 25% had two or more CVD risk factors other than obesity. Obese girls had a significantly higher prevalence of high BP and a higher prevalence of CVD risk factor clustering than nonobese girls.

CONCLUSIONS

Boys had higher glucose concentrations and BP and lower lipid concentrations than girls. We found an association between obesity and higher BP and between obesity and blood glucose and lipid concentrations for both sexes. Clustering of CVD risk factors was especially apparent among the obese children. A clustering of CVD risk factors may begin during early adolescence among the obese.

Relationship between anthropometric variables and lipid levels among school children: The Taipei Children Heart Study

OBJECTIVES

To evaluate the association between anthropometric parameters and lipid levels among Taiwanese school children.

DESIGN AND METHODS

Using a probability-proportional-to size sampling and multi-stages sampling procedure, we sampled 1500 school children from 10 schools in Taipei city. Anthropometric parameters including body weight, body height, waist circumference, hip circumference and skinfolds were measured. Serum total cholesterol (CHOL), triglycerides (TG), high density lipoprotein-cholesterol (HDL-C), apolipoprotein A1 and B (ApoA1 and ApoB) were measured by standard methods, low density lipoprotein-cholesterol (LDL-C) and CHOL/HDL-C ratio were calculated by formula.

RESULTS

We included in our analyses 1366 children (681 boys and 685 girls) with a mean age of 13.3 y (from 12 to 16 y) and with valid anthropometric and biochemical parameters. The boys had higher body height (P < 0.001) and larger body weight (P < 0.05), waist circumference (P < 0.01) and waist/hip ratio (WHR, P < 0.001) than the girls. However, the girls had larger skinfolds than the boys. After adjusting for age, girls had higher total CHOL, TG, HDL-C, LDL-C, ApoA1 and ApoB concentrations than boys. In general, TG was positively associated with most anthropometric parameters (except body height); a similar negative association between HDL-C and anthropometric variables was noted. After controlling, for age, cigarette smoking, alcohol drinking and puberty development, shorter body height was the strongest predictor of total CHOL, LDL-C and ApoB concentrations among boys. Although body mass index (BMI) was a significant positive predictor (P < 0.01) of the CHOL/HDL-C ratio; skinfold measurements were the strongest anthropometric predictors of most lipid concentrations among boys. Among girls, we found WHR and BMI to be the strongest positive predictors of TG and ApoB level respectively (both P < 0.001), but skinfold measurements were best for predicting HDL-C, LDL-C, ApoA1 and the CHOL/HDL-C ratio.

CONCLUSIONS

From this large study of school-age children from Taiwan, we found anthropometric parameters, such as body height, BMI or WHR, are adequate predictors of blood lipid levels; however, skinfold measurements are generally more strongly associated with lipid levels in both genders.

Relationship between smoking status and cardiovascular disease risk factors in young adult males in Taiwan

BACKGROUND

To evaluate smoking status and cardiovascular risk factors in young male adults in Taiwan.

METHODS

After cluster sampling, we performed a cross-sectional survey to assess smoking status, duration, and number of cigarettes smoked in 781 young adult males (mean age 20 years, range 18-24). Cardiovascular disease risk factors, including anthropometric factors, blood pressure, lipoproteins and apolipoprotein levels were also measured.

RESULTS

In total 211 subjects (27.0%) had never smoked, 38 subjects (4.9%) were ex-smokers, and 532 (68.1%) still smoked cigarettes. The prevalence of smoking was higher than in 1989 and 1990 (54.8 and 59.4%, respectively). Current smokers had significantly higher serum triglyceride and lower high-density lipoprotein-cholesterol levels than subjects who had never smoked (56.2 versus 46.9 and 55.6 versus 59.0 mg/dl, respectively; P < 0.05 for both). No difference was found in other cardiovascular risk actors among subjects in the different smoking groups or among current smokers who had smoked for different periods of time or who smoked different numbers of cigarettes.

CONCLUSION

These data suggest that the prevalence of smoking in young adult males in Taiwan has increased progressively. No differences were found in anthropometric factors or blood pressure among subjects of different smoking status. Abnormal lipoprotein levels (higher triglyceride and lower high-density lipoprotein cholesterol) were found in current smokers compared with non-smokers. A longer follow-up study will be needed to confirm whether the smoking status of these young adults can be correlated with the risk of cardiovascular disease.

Anthropometry and lipoproteins-related characteristics of young adult males in Taiwan

OBJECTIVES

To investigate the prevalence of obesity and the lipoprotein-related characteristics among young male adults in the Taiwan area.

DESIGN AND SUBJECTS

After cluster sampling, a cross-sectional survey with a total of 936 males (mean age 20, 18-24) were enrolled.

MAIN OUTCOME MEASURES

The distribution of anthropometric and lipoprotein-related variables and their correlations in young male adults were measured. The prevalence of obesity by different criterion and the lipoprotein characteristics of obese and non-obese were analyzed separately.

RESULTS

The prevalence of obesity was 9.6% by the criterion of body weight greater than 20% of ideal body weight, or 12.6% by the criterion of body mass index (BMI) greater than 25. The obese subjects had significantly higher serum total cholesterol (CHOL), triglyceride (TG) and apo-lipoprotein B (apo B) and lower higher density lipoprotein-cholesterol (HDL-C) levels than the non-obese. The apo A1 levels were 141.3 and 141.9 mg/dl and the lipoprotein [a] (Lp[a]) were 17.4 and 17.1 mg/dl in obese and non-obese respectively, the difference being not statistically significant. Pearson correlation coefficients of body weight, body height, BMI, waist circumference, hip circumference and waist-hip ratio (WHR) to lipoprotein variables showed that both BMI and WHR are positively correlated with CHOL, TG and apo B, but negatively correlated with HDL-C. Furthermore the lipoprotein variables were better correlated with BMI than WHR in lean subjects (BMI < 25). However, this phenomenon was quite different in obese (BMI > 25) subjects, where the WHR was more highly correlated with lipoprotein variables than with BMI.

CONCLUSION

The prevalence of obesity is slightly higher than reported in previous studies in Taiwan. The obese subjects had various abnormal lipoprotein metabolic characteristics, such as higher CHOL, TG, and apo B and lower HDL-C levels than non-obese subjects. The BMI was more highly correlated with lipoprotein variables than was WHR in lean subjects, but the WHR was more highly correlated with lipoprotein variables than was BMI in obese subjects.

The interrelationship between impaired glucose tolerance and other risk factors for cardiovascular disease: is it a predictor for cardiovascular disease?

Glucose intolerance and cardiovascular risk factors were assessed among 215 subjects aged 27-86 years in Ho-long, Taiwan. An oral glucose tolerance test (OGTT) was normal in 107 subjects, impaired in 41 subjects, and abnormal in 67 subjects (as noninsulin dependent diabetes mellitus, NIDDM). Body fatness, blood pressure, carbohydrate and lipid metabolic factors were examined. One-way ANCOVA was used to compare age- and/or BMI-adjusted differences among these groups. Male subjects with NIDDM and impaired glucose tolerance (IGT) had higher systolic (SBP) and diastolic (DBP) blood pressures, plasma insulin (fasting and 1-hour after OGTT), serum triglycerides (TG), heavier body weight, and larger BMI than normal. IGT subjects were also found to have higher TG, insulin (2-hour) and larger insulin area under curve (IAUC) after OGTT than NIDDM. In females, subjects with NIDDM had higher TG, insulin (fasting and 1-hour after OGTT), and larger IAUC than normal. Moreover, female IGT subjects were also found to have significantly higher SBP, DBP, insulin (1-and 2-hour after OGTT), and larger IAUC than both normal and NIDDM subjects. These results suggest that adverse cardiovascular risk factors are present not only in NIDDM subjects, but also in IGT subjects.

Effect of nicardipine treatment on carbohydrate and lipoprotein metabolism in patients with hypertension

This study evaluated the effect of nicardipine, calcium channel blocker, monotherapy on blood pressure and metabolic changes. Various aspect of carbohydrate and lipoprotein metabolism were studied before and after 12 weeks of nicardipine treatment in 23 patients with mild to moderate essential hypertension. Nicardipine was well tolerated and induced a significant decrease (p < 0.001) in both systolic and diastolic blood pressure without any changes in heart rate. Plasma levels of fasting glucose, insulin, C-peptide and hemoglobin A1c, hepatic extraction of insulin were similar following nicardipine treatment. Plasma glucose and insulin responses to an oral glucose challenge did not change in association with nicardipine therapy. Although high density lipoprotein (HDL) cholesterol concentration increased slightly, it did not reach statistical significance. Total cholesterol and low density lipoprotein (LDL) cholesterol levels also increased insignificantly. LDL triglyceride and very low density lipoprotein (VLDL) triglyceride concentrations were higher marginally, which resulted in slightly but insignificantly increase in total triglyceride concentration in association with nicardipine monotherapy for 12 weeks. In conclusion, treatment of patients with mild to moderate hypertension with nicardipine led to lower blood pressure effectively while had no significant influence on carbohydrate and lipoprotein metabolism.

The reappraisal of the association of glycosylated hemoglobin A1c (HbA1c) and blood pressure: a hypertension and diabetes study in a Taiwan rural area

The association of age, body weight, body mass index (BMI) and glycosylated hemoglobin A1c (HbA1c) to blood pressure in the general population of the Ho-long area in Taiwan was examined. A total of 1341 subjects, 746 men and 595 women, aged 40-90 years, were studied. Sex-specific multiple regression analyses were carried out on variables both univariately and significantly associated with blood pressure. Results show HbA1c to be significantly associated with SBP in both males and females before age, weight and/or BMI are adjusted (p < 0.05). After controlling for these confounders, the strength of SBP-HbA1c association was slightly reduced in males, but remained significant. In contrast, there was no significance in females. Moreover, no significant relationship in DBP-HbA1c was found in either sex group. These findings suggest that although a positive correlation was found between HbA1c and SBP, HbA1c or glucose status appeared to be a less important contributing factor in hypertension than age or body weight.

Quality of life assessment in end-stage renal disease patients with maintenance hemodialysis therapy

This is a pilot study assessing the quality of life for a total of twenty uremic patients being treated with maintenance hemodialysis. It includes eight males and twelve females with a mean age of fifty three years, having been on hemodialysis for an average of forty-five months (from five to 143 months). The quality of life study was obtained from a structured questionnaire, which contained 10 categories including: sense of well-being, sense of mood, family life, marriage life, neighborhood relationships, friend relationships, working ability, job condition, intelligence condition and life satisfaction. Each category consisted of 3 to 5 items, with a maximum score of 100 points. Among these 20 patients, the highest score on the quality of life study is marriage life with 80.4 +/- 10.0 points, the lowest score is life satisfaction with 59.7 +/- 15.3 points. There was no significant difference in the scores of quality of life between different sex groups. The scores in the sense of well-being group greater than 60 years were lower than those less than 60 years with a significant difference (P less than 0.05). A significant difference was also found in both the sense of well-being and sense of mood depending on the duration of hemodialysis therapy. Those who received hemodialysis therapy more than 3 years produced better scores in the sense of well-being and sense of mood category than those who received hemodialysis less than 3 years.

[Metabolic effects of chlorothiazide and propranolol on essential hypertension--a double-blind, cross-over design clinical trial]

Several studies have shown that antihypertensive drugs therapy could reduce morbidity and mortality of hypertension related complication such as stroke, congestive heart failure and renal failure, but there was no significant reduction of coronary heart disease. The benefit of the treatment on morbidity and mortality may be counterbalanced by adversed metabolic effects of long-term therapy. The purpose of this study is to evaluate the blood pressure-lowering and adverse metabolic effects of chlorothiazide and propranolol monotherapy. A double-blind, cross-over design clinical trial was performed for 42 cases (22 males and 20 females) with the mean age of 52 (from 30 to 59 years old). After 2 weeks run-in period, the patients were assigned to group A and B with age and sex stratification. Chlorothiazide and propranolol were given for 12 weeks in alternative with 2 weeks placebo washout period. Our studies have shown that, chlorothiazide and propranolol could reduce both systolic and diastolic blood pressure significantly. But they also associated with adverse metabolic effects. Serum uric acid and triglyceride increased and decreased the concentration of high density lipoprotein cholesterol (HDL-C). Those changes could counterbalance the benefit of blood pressure-lowering effect of antihypertension. Carefully monitoring the adverse metabolic effects closely is necessary in therapy with these drugs.

Assessment of proteinuria by using the protein/creatinine ratio of single-voided urine

Quantitative 24-hour urine protein excretion is used in the diagnosis, the monitoring of therapeutic effects and the prognosis of renal disease. However, this method is time-consuming, cumbersome and often inaccurate. Many studies have shown that the single voided urine protein/creatinine (Pr/Cr) ratio relates well with 24-hour urine protein excretion and can be substituted for evaluating some conditions. In our study, 41 patient with renal disease (25 men, 16 women) with a mean age of 43 years (range, 20-79 years), not only collected 24-hour urine, but also collected single voided urine at four different times. There was an excellent correlation between 24-hour urine protein excretion and the single voided urine Pr/Cr ratio at various degrees of creatinine clearance and ranges of proteinuria. The highest correlation was found in urine specimens collected at 16:00 hours with a correlation coefficient (r) of 0.91. Other urine specimens also showed a good relation with a correlation coefficient of above 0.80. The creatinine clearance (Ccr) greater than or equal to 70 ml/min group showed a better relationship than the Ccr less than 70 ml/min group. The proteinuria more than 1.0 g/day group also showed a better relationship than the group with proteinuria of less than 1.0 g/day. However, these differences were not statistically significant. No significant differences between the different age groups or sexes, using the single voided urine Pr/Cr ratio to estimate the 24-hour urine protein excretion were found. It is concluded that the single voided urine Pr/Cr ratio correlates highly with 24-hour urine protein excretion and could be an alternative means for disease monitoring and screening.