Familial history of metabolic disorders and the multiple metabolic syndrome: the NHLBI family heart study

Familial co-aggregation and shared genetics of cardiometabolic disorders and traits: data from the multi-generational Lifelines Cohort Study

BACKGROUND

It is unclear to what extent genetics explain the familial clustering and the co-occurrence of distinct cardiometabolic disorders in the general population. We therefore aimed to quantify the familial (co-)aggregation of various cardiometabolic disorders and to estimate the heritability of cardiometabolic traits and their genetic correlations using the large, multi-generational Lifelines Cohort Study.

METHODS

We used baseline data of 162,416 participants from Lifelines. Cardiometabolic disorders including type 2 diabetes (T2D), cardiovascular diseases, hypertension, obesity, hypercholesterolemia, and metabolic syndrome (MetS), were defined in adult participants. Fifteen additional cardiometabolic traits indexing obesity, blood pressure, inflammation, glucose regulation, and lipid levels were measured in all included participants. Recurrence risk ratios (λR) for first-degree relatives (FDR) indexed familial (co-)aggregation of cardiometabolic disorders using modified conditional Cox proportional hazards models and were compared to those of spouses. Heritability (h2), shared environment, and genetic correlation (rg) were estimated using restricted maximum likelihood variance decomposition methods, adjusted for age, age2, and sex.

RESULTS

Individuals with a first-degree relative with a cardiometabolic disorder had a higher risk of the same disorder, ranging from λFDR of 1.23 (95% CI 1.20-1.25) for hypertension to λFDR of 2.48 (95% CI 2.15-2.86) for T2D. Most of these were higher than in spouses (λSpouses < λFDR), except for obesity which was slightly higher in spouses. We found moderate heritability for cardiometabolic traits (from h2CRP: 0.26 to h2HDL: 0.50). Cardiometabolic disorders showed positive familial co-aggregation, particularly between T2D, MetS, and obesity (from λFDR obesity-MetS: 1.28 (95% CI 1.24-1.32) to λFDR MetS-T2D: 1.61 (95% CI 1.52-1.70)), consistent with the genetic correlations between continuous intermediate traits (ranging from rg HDL-Triglycerides: - 0.53 to rg LDL-Apolipoprotein B: 0.94).

CONCLUSIONS

There is positive familial (co-)aggregation of cardiometabolic disorder, moderate heritability of intermediate traits, and moderate genetic correlations between traits. These results indicate that shared genetics and common genetic architecture contribute to cardiometabolic disease.

Association of Absolute and Relative Handgrip Strength with Prevalent Metabolic Syndrome in Adults: Korea National Health and Nutrition Examination Survey 2014-2018

Maintaining or improving muscular strength may be a key preventive strategy for metabolic syndrome (MetS). However, whether the association of handgrip strength (HGS), as a well-established marker of whole-body muscular strength, with the prevalent metabolic syndrome (MetS) varies with age stratification remains unclear. Additionally, whether absolute of relative HGS is superior to another in predicting MetS is less clear. We examined the association of both relative and absolute HGS with the prevalence of MetS in different age groups. Korean adults aged ≥19 years (n = 28,146; 55.7% female) from the Korean National Health and Nutrition Examination Survey (2014-2018) were examined. HGS was categorized using tertile split (highest, intermediate, lowest) and participants were stratified into different age groups at 10-year intervals. Multivariable logistic regression models were used to examine the association between absolute/relative HGS tertiles and MetS with adjustment for covariates. Lower odds of MetS were observed across lower absolute HGS tertiles and the associations were significant in young participants (19-29 years) in both sexes (odds ratio (OR): 0.59 (95% CI: 0.38-0.92) for intermediate and OR: 0.55 (95% CI: 0.34-0.89) for lowest in males; OR: 0.36 (95% CI: 0.20-0.65) for intermediate and OR: 0.42 (95% CI: 0.24-0.74) for lowest in females; all p < 0.05). By contrast, higher odds of MetS were observed across lower relative HGS in all age groups in both sexes (in total participants, OR: 2.32 (95% CI: 2.06-2.62) for intermediate and OR: 3.69 (95% CI: 3.27-4.16) for lowest in males and OR: 2.04 (95% CI: 1.83-2.28) for intermediate and OR: 3.28 (95% CI: 2.94-3.65) for lowest in females all p < 0.05). The associations of both absolute and relative HGS with MetS attenuated with an increase in age. Our findings suggest that poor relative HGS, as a marker of muscular strength, and not absolute HGS, may be associated with a higher risk of MetS in adults. Our findings also suggest that relative HGS may overestimate MetS in young adults.

Does adjusting for biological maturity when calculating child weight status improve the accuracy of predicting future health risk?

BACKGROUND

The aim of this study was to assess whether adjusting the weight categorisation of children for their biological maturity status could improve the accuracy of predicting weight status and cardiometabolic risk at age 17.

METHODS

Data from 1525 participants (787 female) from the ALSPAC study were analysed. Participants' weight status at age 11 was estimated using first standard chronological age and sex adjusted BMI cut-offs, and again using maturity adjusted BMI cut-offs. Each BMI category at age 11 was regressed against cardiometabolic risk score and BMI category at age 17, controlling for sex, ethnicity and socio-economic status.

RESULTS

At age 11 years, 22% of boys and 46% of girls who were categorised as overweight or having obesity based on chronological age were re-categorised into a lower BMI category after adjusting for biological maturity. Biologically adjusted BMI categories better predicted BMI category at age 17 compared with non-adjusted BMI categories (∆BIC = - 21.69); the odds of having obesity at age 17 were 18.28 times greater with each increase in BMI category at age 11. Adjusted and non-adjusted BMI status at 11 years showed equivalent accuracy in predicting cardiometabolic risk at age 17; the odds ratio of high cardiometabolic risk was 1.85, with heightened risk in boys, particularly early maturers.

CONCLUSION

The traditional method of categorising adolescents into a BMI category may over-predict overweight and obesity, particularly in girls. Adjusting for biological maturity when estimating weight status through calculating adolescents' BMI classification was equivalent to standard approaches in predicting other cardiovascular risk at age 17.

Family History for Cardio-Metabolic Diseases: A Predictor of Major Adverse Cardiovascular Events in Men With Erectile Dysfunction

BACKGROUND

Family history (FH) of cardiovascular (CV) disease is a known CV risk factor. However, it is rarely considered for CV risk stratification. Furthermore, FH for metabolic diseases is generally overlooked.

AIM

To evaluate, in a population of men with erectile dysfunction (ED), whether FH for cardio-metabolic diseases could provide insights into metabolic and sexual features and predict the occurrence of forthcoming major adverse CV events (MACE).

METHODS

A consecutive series of 4,693 individuals (aged 51.3 ± 13.3 years) attending an Andrology outpatient clinic for ED was studied. A subset of these (n = 1,595) was evaluated retrospectively for MACE occurrence.

OUTCOMES

Several metabolic and sexual function-related parameters were studied. For the retrospective study, information on an incident MACE was collected over a mean follow-up of 4.2 ± 2.5 years.

RESULTS

A greater number of cardio-metabolic FH factors were associated with a worse metabolic profile, including higher waist circumference, triglycerides, glucose, glycosylated hemoglobin, and diastolic blood pressure, as well as lower high-density lipoprotein cholesterol. An increased number of FH factors were associated with worse erectile function (odds ratio = 1.14[1.07;1.23], P < .0001), impaired penile dynamic peak systolic velocity, and lower testosterone levels. In the retrospective study, a positive cardiometabolic FH was associated with a significantly higher incidence of MACEs, even after adjusting for age and comorbidities (hazard ratio = 1.51[1.06-2.16], P = .023). Interestingly, when dividing the sample into high- and low-risk categories according to several CV risk factors (age, previous MACEs, high-density lipoprotein cholesterol, and comorbidities), FH was confirmed as a predictor of incident MACE only among the low-risk individuals.

CLINICAL IMPLICATIONS

Investigating FH for cardio-metabolic diseases is a quick and easy task that could help clinicians in identifying, among individuals with ED, those who deserve careful evaluation of CV and metabolic risk factors. Moreover, considering FH for CV risk stratification could predict MACEs in individuals who, according to conventional CV risk factors, would be erroneously considered at low risk.

STRENGTHS & LIMITATIONS

The large sample size and the systematic collection of MACEs through an administrative database, with no risk of loss at follow-up, represent strengths. The use of administrative database for MACE collection may lead to some misclassifications. The specific population of the study limits the generalizability of the results.

CONCLUSION

FH is simple and inexpensive information that should be part of the CV risk assessment in all men with ED because it helps in the identification of those who need lifestyle and risk factor modifications and whose risk would otherwise be overlooked. Rastrelli G, Yannas D, Mucci B, et al. Family History for Cardio-Metabolic Diseases: A Predictor of Major Adverse Cardiovascular Events in Men With Erectile Dysfunction. J Sex Med 2020;17:2370-2381.

The Study of Clustering Effects of Behavior Risk Factors in Patients with Metabolic Syndrome in Southern China: A Cross-Sectional Study

OBJECTIVES

Metabolic syndrome (MetS) is now becoming a serious public health threat. Some behaviors risk factors were considered to be associated with MetS and interacted to adversely affect MetS. However, the clustering effects of behavior risk factors of MetS among Chinese population remain unclear. The aim of this study is to observe the behavior risk factors and their clustering effects of MetS in China.

METHODS

A cross-sectional study design was used. Subjects were recruited in the departments of Cardiology Clinic, Endocrine Clinic, and Health Management from March to December 2019. A demographic sheet was designed to collect the demographic and clinical characteristics of the subjects. International Physical Activity Questionnaire-Short was applied to evaluate the level of PA in this study. Other behavior risk factors were observed by the questionnaire. The stepwise logistic regression analysis was performed to identify the determinants of MetS. The multiple logistic regression analysis was used to analyze the clustering effects of behavior risk factors in MetS.

RESULTS

There are a total of 532 eligible subjects (56.6% females; mean age was 48.4 ± 15.3 years), and approximately 33.3% were diagnosed as MetS. The subjects with a smoking habit (heavy and long-time history) had a 1.833-fold higher risk for MetS than their counterparts (none and light smoking), and the subjects that preferred salty taste had a 1.626-fold higher risk for MetS than the comparison cohort. Smoking and alcohol drinking had the highest clustering effect on MetS among the behavior risk factors.

CONCLUSIONS

The main finding of this study was that smoking and salty taste preference were the independent determinants of MetS. Smoking and alcohol consumption had the highest clustering effect on southern Chinese MetS.

Metabolic syndrome and parental history of cardiovascular disease in young adults in urban Ghana

Background

Metabolic syndrome (MetS) in young adults poses significant cardiovascular diseases (CVD) risk for later years. Parental history of CVDs is known to affect the prevalence of CVD risk in adulthood. In sub-Saharan Africa, the burden of MetS in young adults and its relationship with parental CVDs is largely unknown.

We studied the gender-specific prevalence of MetS and its association with parental history of diabetes, hypertension and CVDs in young adults resident in urban Ghana.

Methods

In a cross-sectional design, 364 young adults aged 20–30 years were randomly recruited from students of University of Ghana. A structured questionnaire was used to collect data on demography, lifestyle, medical and parental medical history. Anthropometric indices and blood pressures were measured. Fasting blood samples were collected to measure plasma levels of glucose, lipid profile, urea and creatinine. MetS was defined according to the Joint Scientific Statement criteria.

Results

The prevalence of MetS was 12.4%, higher in females than male participants (18.4% vs 5.7, p = 0.019). Female participants had higher levels of all the components of MetS than the male participants. Compared to participants with no history of parental CVDs, participants with parental CVDs had a higher proportion of abdominal obesity. A positive history of parental CVDs was associated with increase in odds of MetS [OR (95% CI): 1.23 (1.12–3.04), p = 0.037].

Conclusion

In our study population, there is relatively high prevalence of MetS; higher in females compared to male participants. Parental history of CVDs was associated with MetS.

Increased risk of metabolic disorders in healthy young adults with family history of diabetes: from the Korea National Health and Nutrition Survey

BACKGROUND

We assessed the impact of a family history of diabetes on type 2 diabetes, metabolic syndrome, and behavioral traits in young Korean adults.

METHODS

Subjects aged 25-44 years were included, and the presence of a family history of diabetes was obtained by a self-reported questionnaire (the Korea National Health and Nutrition Survey 2010). We compared the prevalence of type 2 diabetes and metabolic syndrome, and other metabolic parameters, including blood pressure and lipid profile.

RESULTS

Of 2059 participants, those with a family history of diabetes involving first-degree relatives (n = 489, 23.7%) had a significantly higher prevalence of impaired fasting glucose (14.3 vs. 11.7%) and type 2 diabetes (6.7 vs. 1.8%), compared to those without a family history (P < 0.001). The prevalence of metabolic syndrome (21.3 vs. 12.1%, P < 0.001) and its components (except for high-density lipoprotein cholesterol) were greater in subjects with a family history of diabetes. Among subjects exhibiting normal glucose tolerance (n = 1704), those with a family history of diabetes had higher fasting glucose (89.0 vs. 87.8 mg/dL, P < 0.001) and triglyceride (100.5 vs. 89.0 mg/dL, P < 0.001), and lower beta cell function by the homeostasis model assessment (HOMA-β; 134.2 vs. 137.5, P = 0.020). The obesity indices (body mass index, waist circumference, and triglyceride) were significantly correlated with those of both parents (P < 0.01 for all variables). Risk-reducing behavior, including regular exercise (18.2 vs. 19.7%, P = 0.469) and calorie intake (2174.8 vs. 2149.1 kcal/day, P = 0.636), did not markedly differ according to a family history of diabetes.

CONCLUSIONS

Young adults with a family history of diabetes had an increased risk of type 2 diabetes and metabolic syndrome, even though they currently exhibited a normal glycemic profile. Proactive lifestyle consultation is requested especially among healthy young population with a family history of diabetes.

The association of type 2 diabetes patient and spouse illness representations with their well-being: a dyadic approach

BACKGROUND

The aim of this study was to examine the relation between certain illness representations and the physical and psychological well-being of persons with type 2 diabetes mellitus and their spouses.

PURPOSE

In this study, we examined the relation of type 2 diabetes patients and their spouses' representations of illness consequences and timeline (chronicity and cyclicality/predictability) to the physical and psychological well-being of both. The interaction between patient and spouse illness representations was also studied.

METHODS

A dyadic analysis approach was employed, while the Actor-Partner Interdependence Model was used to examine dyadic effects. One hundred and sixty-eight individuals nested in 84 couples participated.

RESULTS

Regarding illness representations, both actor (i.e., the effects of a person's own characteristics on own outcomes) and partner (i.e., the effects of the partner's characteristics on a person's outcomes) effects were identified but only for patients' well-being. Certain significant interactions were also found: patients' timeline-cyclical representations were weakly associated with their anxiety and depression symptoms when spouses perceived diabetes as less unpredictable. Also, spouses' perceptions of consequences were more strongly related to their anxiety when patients perceived diabetes as less burdensome.

CONCLUSIONS

Overall, the findings indicate a type of synergy between patient and spouse illness representations. They also emphasize the interdependence between diabetes patients and their partners, and the need to examine adaptation to illness within a dyadic-regulation framework as well.

Association of self-reported familial history of cardiometabolic disease with metabolic syndrome in apparently healthy urban Colombian men

OBJECTIVES

Evidence about the relationship between familial history (FH) of cardiometabolic disease (CMD) and metabolic syndrome (MetS) in Latin American populations is scarce. The aim of this study was to evaluate the relationship of FH of CMD and of dyslipidemia and obesity with MetS in healthy men.

METHODS

One-hundred-twenty one individuals were recruited. Waist circumference and blood pressure were measured by a trained researcher using standard techniques. Glycemia and lipid profile were determined by colorimetric assays. A survey to record personal data and family antecedents in siblings, aunts/uncles, parents, and grandparents was conducted by trained interviewers.

RESULTS

Individuals having three or more familial antecedents were associated with high triglycerides level even after adjusting by age, sedentarism, fat and carbohydrates intake, and alcohol consumption. After adjusting for the same variables, FH of dyslipidemia and hypertension was also associated with high triglycerides levels and elevated waist circumference, respectively. The FH of stroke was associated with high blood pressure after adjusting for the rest of familial antecedents, and with MetS in all adjustment models.

DISCUSSION

the findings of association of this study together with the previous reports are evidence of the importance of hereditary component as independent predictor of cardiovascular risk factors and its clustering, as well as of possible specific association patterns between FH of CMD and MetS depending on evaluated population in terms of ethnic groups and geographic region. Further studies are required in other populations, as well as exploration of genetic markers of CMD regarding to MetS.

Does family history of metabolic syndrome affect the metabolic profile phenotype in young healthy individuals?

BACKGROUND

Early identification of high-risk individuals is key for the prevention of cardiovascular disease (CVD). The aim of this study was to assess the potential impact of a family history of metabolic syndrome (fhMetS) on the risk of metabolic disorders (abnormal body mass, lipid profile, glucose metabolism, insulin resistance, and blood pressure) in healthy young individuals.

METHODS

We studied CVD risk factors in 90 healthy volunteers, aged 27-39 years; of these, 78 had fhMetS and 12 were without fhMetS (control group). Fasting serum lipids, glucose, and insulin levels were assayed, and anthropometric parameters and blood pressure using, an ambulatory blood pressure monitoring system, were measured. Nutritional and physical activity habits were assessed.

RESULTS

Despite similar nutritional and physical activity habits, abnormal body mass was found in 53.2% of the fhMetS participants and 46.1% of the control participants (p = 0.54). The occurrence of obesity was 19.4% and 0%, respectively (p = 0.69). Compared to the control participants, fhMetS was associated with significantly higher total cholesterol (5.46 mmol/L vs. 4.69 mmol/L, p < 0.030), low-density lipoprotein cholesterol ( 3.28 mmol/L vs. 2.90 mmol/L, p < 0.032), and non-high-density lipoprotein cholesterol ( 3.74 mmol/L vs. 3.25 mmol/L, p < 0.016) levels, in addition to lower fasting glucose levels ( 4.51 mmol/L vs. 4.81 mmol/L, p < 0.042). A positive correlation between fasting glucose and insulin levels (r = 0.28; p < 0.015) was detected in the fhMetS participants. Higher mean daytime systolic blood pressure (121.5 mmHg vs. 113.3 mmHg, p < 0.035), mean daytime diastolic blood pressure ( 79.0 mmHg vs. 74.5 mmHg, p < 0.045), and mean nighttime diastolic blood pressure ( 64.0 mmHg vs. 59.5 mmHg, p < 0.019) were observed in the fhMetS group.

CONCLUSIONS

More than 50% of the fhMetS participants had excess weight or a lipid disorder, which may indicate an increased risk of cardiovascular disease and the need for regular ambulatory assessment of serum lipid concentrations in young people with a family history of MetS.

Parental obesity and risk factors for cardiovascular disease among their offspring in mid-life: findings from the 1958 British Birth Cohort Study

Background:

Few studies have investigated whether parental adiposity is associated with offspring cardiovascular health or the underlying pathways. Studying these associations may help to illuminate the paradox of increasing prevalence of obesity and declining trends in cardiovascular disease (CVD) mortality, which may be partially explained by beneficial adaptations to an obesogenic environment among people exposed to such environments from younger ages.

Objective:

To investigate associations between parental body mass index (BMI) and risk factors for CVD among their offspring in mid-life and to test whether associations of offspring BMI with CVD risk factors were modified by parental BMI.

Methods:

Data from parents and offspring in the 1958 British birth cohort were used (N=9328). Parental BMI was assessed when offspring were aged 11 years; offspring BMI, waist circumference and CVD risk factors (lipid levels, blood pressure, glycosylated haemoglobin (HbA1c) and inflammatory and haemostatic markers) were measured at 44–45 years.

Results:

Higher parental BMI was associated with less favourable levels of offspring risk factors for CVD. Most associations were maintained after adjustment for offspring lifestyle and socioeconomic factors but were largely abolished or reversed after adjustment for offspring adiposity. For some CVD risk factors, there was evidence of effect modification; the association between higher BMI and an adverse lipid profile among offspring was weaker if maternal BMI had been higher. Conversely, offspring BMI was more strongly associated with HbA1c if parental BMI had been higher.

Conclusions:

Intergenerational influences may be important in conferring the effect of high BMI on CVD risk among offspring.

Endothelin Type A Receptor Genotype is a Determinant of Quantitative Traits of Metabolic Syndrome in Asian Hypertensive Families: A SAPPHIRe Study

Co-heritability of hypertension and insulin resistance (IR) within families not only implies genetic susceptibility may be responsible for these complex traits but also suggests a rational that biological candidate genes for hypertension may serve as markers for features of the metabolic syndrome (MetS). Thus we determined whether the T323C polymorphism (rs5333) of endothelin type A (ETA) receptor, a predominant receptor evoking potent vasoconstrictive action of endothelin-1, contributes to susceptibility to IR-associated hypertension in 1694 subjects of Chinese and Japanese origins. Blood pressures (BPs) and biochemistries were measured. Fasting insulin level, insulin-resistance homeostasis model assessment (HOMAIR) score, and area under curve of insulin concentration (AUCINS) were selected for assessing insulin sensitivity. Genotypes were obtained by methods of polymerase chain reaction-restriction fragment length polymorphism. Foremost findings were that minor allele frequency of the T323C polymorphism was noticeable lower in our overall Asian subjects compared to multi-national population reported in gene database; moreover both the genotypic and allelic frequencies of the polymorphism were significantly different between the two ethnic groups we studied. The genotype distributions at TT/TC/CC were 65, 31, 4% in Chinese and 51, 41, 8% in Japanese, respectively (p < 0.0001). Additionally, carriers of the C homozygote revealed characteristics of IR, namely significantly higher levels of fasting insulin, HOMAIR score, and AUCINS at 29.3, 35.3, and 39.3%, respectively, when compared to their counterparts with TT/TC genotypes in Chinese. Meanwhile, the CC genotype was associated with a higher level of high density lipoprotein cholesterol in Japanese. No association of the polymorphism with BP was observed. This study demonstrated for the first time that T323C polymorphism of ETA receptor gene was associated with an adverse insulin response in Chinese and a favorite atherogenic index in Japanese.

Family History of Diabetes, Acculturation, and the Metabolic Syndrome among Mexican Americans: Proyecto SALSA

BACKGROUND

The purpose of this study was to examine effect modifiers of the relationship between family history of diabetes, a proxy for genetic predisposition, and the metabolic syndrome.

METHODS

Subjects were a cross-sectional sample of 205 Mexican-Americans patients of the San Ysidro Health Center in San Diego County. Self-reported parental history of diabetes was examined as a risk factor for individual metabolic syndrome traits (hyperglycemia, hypertension, abdominal obesity, hypertriglyceridemia and low HDL-cholesterol) and a composite phenotype, defined both by standard modified National Cholesterol Education Program- Adult Treatment Panel III (NCEP-ATPIII) criteria and using principal components analysis, in age and sex-adjusted multiple logistic and linear regression models.

RESULTS

Family history of diabetes was most strongly associated with individual traits of hyperglycemia (P = .0002) and low HDL-C (P = .001) and conferred a significant increased odds of metabolic syndrome defined by both NCEP-ATPIII criteria (odds ratio 3.57, 95% confidence interval 1.82, 7.01; P = .0002) and by principal components analysis (P = 0.003). Moreover, the family history association with metabolic syndrome was modified by number of years living in the United States (interaction P = .04). This same effect was not seen for diabetes (P = .19).

CONCLUSIONS

The results of our study support a common etiology for at least some components of the metabolic syndrome, especially hyperglycemia and low HDL-cholesterol, the basis of which may be genetic. Moreover, the effect of genes on these traits may be modified by longer duration in the United States, supporting the concept of gene-environment interaction in the development of the metabolic syndrome.

Prevalence and determinants of the metabolic syndrome among Tunisian adults: results of the Transition and Health Impact in North Africa (TAHINA) project

OBJECTIVE

To determine the prevalence of metabolic syndrome (MetS) and its components and to evaluate the relationship between this diagnosis and cardiovascular risk factors, demographic and socio-economic variables.

DESIGN

A cross-sectional study using a questionnaire including information on sociodemographic and CVD risk factors. Blood pressure, anthropometric indices, fasting glucose and lipid profile were measured. MetS was defined according to the criteria of the National Cholesterol Education Program, Adult Treatment Panel III.

SETTING

The whole Tunisian territory; Transition and Health Impact in North Africa (TAHINA) project.

SUBJECTS

A total of 4654 individuals (1840 men and 2814 women), aged 35 to 74 years, who participated in the Tunisian national survey.

RESULTS

The overall prevalence of MetS was 30·0 %, higher in women (36·1 %) than in men (20·6 %; P < 0·001). In both genders MetS prevalence increased significantly with age (P < 0·001), but this increase was more important in women. Multiple regression analyses showed that the odds for MetS increased significantly with urban area for both men and women (P < 0·05 and P < 0·001, respectively). The multivariate models showed also that the odds for MetS increased significantly with increasing level of education and in those with a family history of CVD for men (both P < 0·05) and after the menopausal transition for women (P < 0·05).

CONCLUSIONS

The study highlights the MetS problem in a middle-income developing country. There is an urgent need for a comprehensive, integrated, population-based intervention programme to ameliorate the growing problem of MetS in Tunisians.

Familial concordance of metabolic syndrome in Korean population--Korean National Health and Nutrition Examination Survey 2005

AIMS

To investigate the familial concordance of metabolic syndrome and its components in a nationally representative survey in Korean.

METHODS

We used data from the Korean National Health and Nutrition Examination Survey (KNHANES), a nationwide survey examining the general health and nutritional status of the Korean people. We enrolled 1641 married couples and 1527 parents-1342 offspring.

RESULTS

Prevalence of the metabolic syndrome was 17.1% for husbands, 11.7% for wives, 14.3% for parents, and 7.2% for offspring. After adjustment for age, there were strong positive correlations between family members for the metabolic variables. Compared with husbands whose wives did not have metabolic syndrome, adjusted odds ratio in husbands whose wives had metabolic syndrome was 1.43 (95% CI: 1.10-1.87) for the risk of having metabolic syndrome. Similarly, wives whose husbands had metabolic syndrome had 1.41 (95% CI: 1.08-1.84) times higher risk of having metabolic syndrome. Compared with children whose parents did not have metabolic syndrome, adjusted odds ratio in children with at least one parent with the metabolic syndrome was 2.56 (95% CI: 1.09-5.98) for the metabolic syndrome.

CONCLUSIONS

Our study revealed that there is significant familial concordance for metabolic syndrome and its components in Korean families.

Cultural variations in attitudes towards family risk of diabetes

AIMS

To examine differences in attitudes and behaviours towards familial risk of type 2 diabetes in populations in Ireland and Bahrain.

METHODS

Cross-sectional ecological study. Questionnaires were developed and administered to patients with diabetes and their first degree relatives in both Bahrain and Ireland. Data was analysed using non-parametric tests of association.

RESULTS

Responses were compared between 297 patients with diabetes from Ireland and 201 from Bahrain and between 364 relatives of patients with diabetes in Ireland and 244 from Bahrain. Relatives in Bahrain had more knowledge of risk factors for diabetes and an increased perception of the seriousness of diabetes but a more external, chance locus of control and perceived more barriers to changing lifestyles than those in Ireland. There was no difference in perception of personal risk of diabetes.

CONCLUSIONS

Knowledge of risk factors and seriousness of diabetes are higher in Bahrain than in Ireland but perception of personal risk of diabetes and intention to adopt risk reducing behaviours are no different. There is a need to develop models of behavioural change that are more relevant to the needs of the Bahraini population in reducing their risk of diabetes.

Family history in public health practice: a genomic tool for disease prevention and health promotion

Family history is a risk factor for many chronic diseases, including cancer, cardiovascular disease, and diabetes. Professional guidelines usually include family history to assess health risk, initiate interventions, and motivate behavioral changes. The advantages of family history over other genomic tools include a lower cost, greater acceptability, and a reflection of shared genetic and environmental factors. However, the utility of family history in public health has been poorly explored. To establish family history as a public health tool, it needs to be evaluated within the ACCE framework (analytical validity; clinical validity; clinical utility; and ethical, legal, and social issues). Currently, private and public organizations are developing tools to collect standardized family histories of many diseases. Their goal is to create family history tools that have decision support capabilities and are compatible with electronic health records. These advances will help realize the potential of family history as a public health tool.

Genome-wide linkage analysis of multiple metabolic factors: evidence of genetic heterogeneity

The metabolic syndrome is a highly complex disease and has become one of the major public-health challenges worldwide. We sought to identify genetic loci with potential influence on multiple metabolic factors in a white population in Beaver Dam, Wisconsin, and to explore the possibility of genetic heterogeneity by family history of diabetes (FHD). Three metabolic factors were generated using principal-component factor analysis, and they represented: (i) glycemia, (ii) blood pressure, and (iii) combined (BMI, high-density lipoprotein (HDL) cholesterol, and serum uric acid) factors. Multipoint model-free linkage analysis of these factors with 385 microsatellite markers was performed on 1,055 sib-pairs, using Haseman-Elston regression. Genome-wide suggestive evidence of linkage was found at 30 cM on chromosome 22q (empirical P (P(e)) = 0.0002) for the glycemia factor, at 188-191 cM on chromosome 1q (P(e) = 0.0007) for the blood pressure factor, and at 82 cM on chromosome 17q (P(e) = 0.0007) for the combined factor. Subset analyses of the families by FHD showed evidence of genetic heterogeneity, with divergent linkage signals in the subsets on at least four chromosomes. We found evidence of genetic heterogeneity by FHD for the three metabolic factors. The results also confirmed findings of previous studies that mapped components of the metabolic syndrome to a chromosome 1q region.

Reducing health risk in family members of patients with type 2 diabetes: views of first degree relatives

Background

Patients with type 2 diabetes can have an important role in discussing health risk within families. This study aimed to establish the acceptability to first degree relatives towards their relative with type 2 diabetes intervening as health promoters in their own families, using the Health Belief Model as a theoretical framework for evaluation.

Methods

Cross-sectional questionnaire design. Survey questionnaire for first degree relative (sibling or child) mailed to a random sample of patients with type 2 diabetes registered with an urban hospital diabetes clinic (n = 607 eligible patients). Patients were asked to pass on questionnaires to one to two first degree relatives.

Results

Questionnaires were returned from 257 families (42% response rate) with two responses provided by 107 families (a total of 364 questionnaires). The majority (94%) of first degree relatives of patients with type 2 diabetes would like to be informed about reducing their risk. Half (48%) of respondents reported being spoken to by a relative with type 2 diabetes about their risk of diabetes. Those spoken to were more likely to see themselves at risk of diabetes, to worry about developing diabetes and to view diabetes as a serious condition.

Conclusions

A role for patients with type 2 diabetes in discussing health risk in their family appears to be acceptable to many relatives. Discussion of risk and interventions to reduce health risk with their relatives should be encouraged in patients with type 2 diabetes.

Will people with type 2 diabetes speak to family members about health risk?

OBJECTIVE

This study aimed to assess the potential for communication of familial risk by patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

A questionnaire was completed by a random sample of patients with type 2 diabetes registered with a hospital diabetes clinic.

RESULTS

Two-thirds of patients (65%) had spoken to at least one sibling or child about diabetes risk. They were more likely to believe their family was at risk, to worry about their family developing diabetes, and to be aware of the seriousness of diabetes. The results revealed greater awareness of family risk of type 2 diabetes compared with those from previous studies.

CONCLUSIONS

Many patients with type 2 diabetes had already taken the initiative, without formal prompting, to talk to family members about their risk of diabetes. Discussion of risk and interventions to reduce risk should be encouraged within families.

Factor relationships of metabolic syndrome and echocardiographic phenotypes in the HyperGEN study

BACKGROUND

Metabolic syndrome and its risk factors are predictors of cardiovascular events. Metabolic syndrome is also directly associated with echocardiographic phenotypes.

METHODS

The current study is the first to investigate the factors associated with both metabolic syndrome risk factors and echocardiographic phenotypes and assess their heritability. Multivariate factor analysis was performed on 15 traits in 1393 African-Americans and 1133 whites, as well as stratified by type 2 diabetes mellitus status.

RESULTS

Factor analysis with varimax rotation established four to five latent factors across ethnicities and diabetes mellitus stratifications. Among metabolic syndrome risk factors, blood pressure was the most highly correlated with cardiac traits. The factor domains, in the order of the proportion of variance explained, were 'left ventricle wall thickness', 'left ventricle geometry', 'blood pressure', 'BMI-insulin', and 'lipid-insulin'. Factor analysis without any rotation identified special (cross domain) metabolic syndrome-echocardiographic factors, 'blood pressure-left ventricle geometry' and 'blood pressure-left ventricle dimension-wall thickness' in whites. Fifty to 57% of the total original risk factor variance was explained by the latent factors. Heritability was highest for BMI-insulin (37-53%), lowest for 'blood pressure' factors (15-27%), and intermediate for metabolic syndrome-echocardiographic factors.

CONCLUSION

These latent factors identified can be utilized as summary phenotypes in epidemiological, linkage, and association studies.

Examining metabolic syndrome definitions in overweight Hispanic youth: a focus on insulin resistance

OBJECTIVE

To examine the prevalence of the metabolic syndrome in overweight Hispanic youth according to 3 published pediatric definitions. Furthermore, the relationship of each definition to directly measured insulin resistance was examined.

STUDY DESIGN

We conducted a secondary data analysis of 218 overweight Hispanic youth with a family history of type 2 diabetes mellitus. The metabolic syndrome was defined as >/=3 of these criteria: elevated triglyceride level, low high-density lipoprotein cholesterol level, elevated blood pressure, abdominal obesity, and hyperglycemia. The cutoff points were derived from updated definitions of Cook et al,(1) Cruz et al,(2) and Weiss et al.(3) Insulin sensitivity was determined with the insulin-modified frequently sampled intravenous glucose tolerance test.

RESULTS

Prevalence of the metabolic syndrome ranged from 25.7% to 39%, with moderate to substantial agreement between definitions (kappa = 0.52-0.70). Regardless of definition, an inverse relationship between metabolic risk and insulin sensitivity was noted such that children with the metabolic syndrome had 51% to 60% lower insulin sensitivity compared with children without any risk factors (P </=.001 for all definitions).

CONCLUSION

The metabolic syndrome is prevalent in overweight Hispanic youth and may provide pediatricians with additional clinical insight for identifying the most metabolically at-risk children. Working toward a uniform and practical definition of the metabolic syndrome may improve its clinical implementation.

Familial aggregation of metabolic syndrome and its components in a large Chinese population

OBJECTIVE

To investigate the familial aggregation of metabolic syndrome (MetS) and its components in the Chinese.

METHODS AND PROCEDURES

A total of 17,954 subjects from 5,224 families with multiple siblings aged 25-64 years old (mean age 45.8 years, 51.6% male) were enrolled from a rural area of Anhui Province of China during 2004-2005. Anthropometric measurement, body composition, blood pressure, plasma lipids, and fasting glucose and insulin, as well as a questionnaire interview, were obtained from each participant.

RESULTS

Significant correlations among siblings were observed in all the traits examined, including BMI, waist circumference, total body and abdominal fat percentage, fasting plasma glucose (FPG) and insulin, insulin resistance index of homeostatic model assessment (HOMA-IR), total cholesterol, triglyceride, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol, and blood pressure, after adjustment for age, gender and some other covariates. The correlation coefficients varied from 0.18 for FPG to 0.42 for HDL-C. In stratified analyses, we found siblings with a smaller age gap among them had higher intraclass correlation coefficients (ICCs) for most of the above phenotypes than those with a greater age difference, and the correlation of systolic blood pressure (SBP) was stronger in male siblings than that in female. If the eldest sibling is affected by MetS or any of its components, younger siblings bear a twofold to threefold higher risk for developing MetS or any of its components than those with a healthy eldest sibling.

DISCUSSION

Our study demonstrated a significant familial resemblance as regards MetS and its components among the Chinese. Further studies are warranted to investigate specific genetic and environmental factors related to MetS in this population.

The Prevalence of Metabolic Syndrome in Various Populations

The insulin resistance/metabolic syndrome is characterized by the variable co-existence of hyperinsulinemia, obesity, dyslipidemia (small dense low-density lipoprotein, hypertriglyceridemia, and decreased high-density lipoprotein cholesterol), and hypertension. The pathogenesis of the syndrome has multiple origins. However, obesity and sedentary lifestyle coupled with diet and still largely unknown genetic factors clearly interact to produce the syndrome. This multifactorial and complex trait of metabolic syndrome leads to increased risk of cardiovascular disease. The scope of this review is to examine the differences in prevalence of the metabolic syndrome in various groups (eg, according to age, sex, ethnicity, social status, or presence of obesity) that could help with the better understanding of the pathogenesis of this syndrome. This review also considers the impact of metabolic syndrome on cardiovascular disease.

Longitudinal and age trends of metabolic syndrome and its risk factors: the Family Heart Study

Background

We report longitudinal changes in the metabolic syndrome (MetS) in 2,458 participants from 480 families in the Family Heart Study. Participants were examined between 1994–96 (FHS-T1) and 2002–03 (FHS-T2), about 7.4 years apart. Additionally, the impact of medication on estimates of MetS prevalence, and associations of MetS with prevalent coronary heart disease (CHD) and type 2 diabetes (T2D) were studied.

Methods

Three definitions for MetS prevalence were considered. One represented the original (o) National Cholesterol Education Program (NCEP) MetS criteria. Two others considered the confounding of medications effects, respectively (m) lipid medications constituted a categorical diagnostic criterion for lipids variables, and (c) lipids and blood pressure variables were corrected with average clinical trials medications effects. Logistic regression of MetS on CHD and T2D, as well as the trend analysis of MetS by age, were performed.

Results

MetS increased from 17.1% in FHS-T1(o) to 28.8% in FHS-T2(o); from 19.7% in FHS-T1(m) to 42.5% in FHS-T2(m); and from 18.4% in FHS-T1(c) to 33.6% in FHS-T2(c). While we observed adverse changes in all risk factors, the greatest increase was for waist circumference (25%). The percentages of MetS were about 2 to almost 3 times higher in ages 50 years and older than in younger ages. The odds of having prevalent CHD were about 2.5 times higher in the subjects classified with MetS than without.

Conclusion

MetS percentages increased noticeably longitudinally and cross-sectionally with older age. These conclusions were reached with and without considering medication use, but correcting risk factors for medications use affects the MetS prevalence estimates. As found in other studies, MetS was associated with increased odds for prevalent CHD.

Relationship between metabolic syndrome and familial history of hypertension/stroke, diabetes, and cardiovascular disease

This research analyzes the prevalence of metabolic syndrome (MS) in Korea and examines how the presence of a familial history of diseases related to MS, such as hypertension/stroke, cardiovascular disease, and diabetes, affect the development of MS in Koreans. The prevalence of MS and its components, as defined by the Nation-al Cholesterol Education Program Adult Treatment Panel guidelines, were evaluated in nationally representative samples of non-institutionalized civilian Koreans. This analysis is based on the 2001 Korea National Health and Nutrition Examination Survey, which used a stratified multistage probability sampling design. The final study included 5,742 adults who had completed the necessary health examinations and met the diagnosis of MS. The prevalence of MS was 25.5% in men and 28.7% in women. Odds ratio for MS among men with a familial history of hypertension/stroke was higher than that among men who did not have this history. The OR for MS among women with a familial history of hypertension/stroke or diabetes was higher than that among women who had no familial history of these diseases. These results show that familial history of hypertension/stroke and diabetes was significantly related to the presence of MS in both young men and women.

Association of increased cardiorespiratory fitness with low risk for clustering of metabolic syndrome components in asymptomatic men

BACKGROUND

From a preventive aspect, it is especially important to investigate the lifestyle risk factors associated with cardiovascular disease (CVD). The purpose of this study was to determine the relationship of increasing metabolic syndrome (MS) components across increasing levels of estimated cardiorespiratory fitness (CRF) in asymptomatic young to middle-aged men.

METHODS

We studied 449 consecutive asymptomatic men (47 +/- 7 years) who underwent a maximal treadmill exercise test according to the Bruce protocol. Cardiorespiratory fitness (CRF) was divided into tertiles based on metabolic equivalents (METs). The following MS components were studied: 1) waist circumference > 102 cm; 2) serum triglycerides > or = 150 mg/dL; 3) HDL cholesterol levels of < 40 mg/dL; 4) fasting blood glucose (FBG) > or = 110 mg/dL or 5) blood pressure > or = 130/85 mmHg or treated hypertension. Multinomial logistic regression was used to investigate the relationship between clustering of MS components and CRF as determined by metabolic equivalents (METs). We used polytomous logistic regression to determine the likelihood of clustering of increasing components of metabolic syndrome with intermediate (2nd tertile) and low (1st tertile) levels of CRF as compared to those with highest levels of CRF (3rd tertile).

RESULTS

Overall in the study population, zero, 1, 2 and > or = 3 (i.e., metabolic syndrome) risk factors for MS were observed in 29% (n = 129), 26% (n = 118), 22% (n = 98) and 23% (n = 104) men, respectively. The mean METS achieved in the study population was 10 +/- 2 (range 4-20). Nearly half (49%) of individuals with the highest levels of CRF had no MS risk factors whereas only 18% of those with low CRF (METS < 9) had no MS risk factors. On the other end of the spectrum, the prevalence of MS (> or = 3 MS risk factors) increased significantly across decreasing levels of CRF (6, 22, 33% p < 0.0001 for trend). Multivariable polytomous logistic regression (adjusting for age, smoking, cholesterol-lowering therapy) demonstrated that individuals with low CRF (1st tertile of METS) compared to those with highest CRF had 3.1- (p = 0.001) and 11.8- (p < 0.0001) fold higher risk of having 2 and > or = 3 MS components, respectively. Similar results were observed when the analyses was repeated adjusting for Framingham risk score.

CONCLUSIONS

Asymptomatic men with low levels of CRF have a greater likelihood for clustering of MS components and thus are at higher CVD risk. Further studies are needed to define the risk of cardiovascular disease in patients with intermediate levels of CRF and address which treatment strategies are most important given an individual's risk profile.

Quantitative trait loci for metabolic syndrome in the Hypertension Genetic Epidemiology Network study

As part of the Hypertension Genetic Epidemiology Network study, genome scans were performed in two ethnicities on the categorical metabolic syndrome (MetS). Genome scans were performed also on the factor scores produced by factor analysis (quantitative MetS). Heritabilities were highest for the obesity-insulin (INS) factor and lowest for blood pressure (BP) and central obesity. Seventeen unique putative quantitative trait loci (QTLs) yielded logarithm of the odds ratio (LOD) scores in excess of 1.7, 8 for blacks and 9 for whites. Important QTL findings in whites included an LOD score of 3.19 on chromosome 15q15 for the BP factor, 3.08 on chromosome 8p23 for the lipids-INS factor, and 3.07 on chromosome 3p26 for the obesity-INS factor. In blacks, after excluding type 2 diabetics, important QTLs were identified, including an LOD score of 2.77 on 13p12 for the obesity-INS factor and 2.63 on chromosome 11q24 for the lipids-INS factor. Categorical MetS had lower results than quantitative MetS. Notably, several loci identified overlap with those identified in other studies for a single or group of traits. The most promising candidate loci on 11q24 for lipids-INS and 13p12 for obesity-INS in blacks, 8p23 for lipids-INS, 14q24 for obesity-INS, and 15q15 for BP in whites warrant further investigation.

Association between the metabolic syndrome and parental history of premature cardiovascular disease

AIMS

The goal of this study is to assess the association between the metabolic syndrome (MS) and parental history of cardiovascular disease (CVD).

METHODS AND RESULTS

Participants were recruited in a population survey of 3441 men and women, aged 35-64. MS was defined with NCEP-III guidelines. Familial history of myocardial infarction (MI), angina, and stroke was assessed with a standardized questionnaire. Parental premature CVD was defined if CVD occurred before 55/65 years in the father/mother. A total of 390 men and 281 women had MS. Positive parental CVD was associated with MS in women (43.0 vs. 36.8%, P<0.001) but not in men (36.9 vs. 31.8%, P=0.06). Similarly, parental premature CVD was associated with MS in women (19.2 vs. 11.8%, P<0.0007) but not in men (11.1 vs. 11.1%, ns). In women with MS, the age, centre, and educational level adjusted odds ratios [OR (95% CI)] of having a positive parental premature stroke was 1.84 (1.0-3.38), P=0.049. This OR was 1.76 (1.23-2.76), P=0.007 for combined parental premature MI and stroke and 1.67 (1.17-2.38), P=0.004 for combined premature MI, stroke, and angina. After further adjustment on personal coronary heart disease and CVD risk factors, the ORs of having a positive parental history of combined premature MI and stroke [1.75 (1.11-2.76), P=0.016] or MI, stroke, and angina [1.79 (1.21-2.63), P=0.003], remained statistically significant, in women with MS.

CONCLUSION

The MS is associated with parental premature CVD independently of classical CV risk factors, suggesting that MS is a contributor to the familial aggregation of premature CVD.

An evaluation of the metabolic syndrome in a large multi-ethnic study: the Family Blood Pressure Program

BACKGROUND

The Family Blood Pressure Program is an ongoing, NHLBI-sponsored, multi-center program to study the genetic determinants of high blood pressure. The goal of this particular study was to study patterns of metabolic syndrome (MetS) in four ethnic groups: African Americans, Caucasians, Hispanics, and Asians.

METHODS

A major part of participants in three networks GENOA, HyperGEN and SAPPHIRe were recruited mainly through hypertensive probands. MetS was defined as a categorical trait following the National Cholesterol Education Program definition (c-MetS). MetS was also characterized quantitatively through multivariate factor analyses (FA) of 10 risk variables (q-MetS). Logistic regression and frequency tables were used for studying associations among traits.

RESULTS

Using the NCEP definition, the Hispanic sample, which by design was enriched for type 2 diabetes (T2D), had a very high prevalence of MetS (73%). In contrast, its prevalence in Chinese was the lowest (17%). In African Americans and Hispanics, c-MetS was more prevalent in women than in men. Association of c-MetS with type 2 diabetes (T2D) was prominent in the Hispanics and African Americans, less pronounced in the Whites and Japanese, (although still significant), and weakest in the Chinese sample. Using FA without rotation, we found that the main factor loaded obesity (OBS) and blood pressure (BP) in African Americans; OBS and insulin (INS) in Hispanics, in Japanese, and in Whites; and OBS alone in Chinese. In Hispanics, Whites, and Japanese, BP loaded as a separate factor. Lipids in combination with INS also loaded in a separate factor. Using FA with Varimax rotation, 4 independent factors were identified: "Obesity-INS," "Blood pressure," "Lipids-INS," and "Central obesity." They explained about 60% of the variance present in the original risk variables.

CONCLUSION

MetS ethnic differences were identified. Ascertaining for hypertension or T2D increased the MetS prevalence in networks compared with the one in the US general population. Obesity was the most prominent risk factor contributing to both c-MetS and q-MetS. INS contributed in two important factors (obesity and lipids). The information imbedded into c-MetS trait /q-MetS factors scores can contribute in future research of the MetS, especially its utilization in the genetic analysis.

An evaluation of the metabolic syndrome in the HyperGEN study

BACKGROUND: In 2001 the National Cholesterol Education Program (NCEP) provided a categorical definition for metabolic syndrome (c-MetS). We studied the extent to which two ethnic groups, Blacks and Whites were affected by c-MetS. The groups were members of the Hypertension Genetic Epidemiology Network (HyperGEN), a part of the Family Blood Pressure Program, supported by the NHLBI. Although the c-MetS definition is of special interest in particular to the clinicians, the quantitative latent traits of the metabolic syndrome (MetS) are also important in order to gain further understanding of its etiology. In this study, quantitative evaluation of the MetS latent traits (q-MetS) was based on the statistical multivariate method factor analysis (FA). RESULTS: The prevalence of the c-MetS was 34% in Blacks and 39% in Whites. c-MetS showed predominance of obesity, hypertension, and dyslipidemia. Three and four factor domains were identified through FA, classified as "Obesity," "Blood pressure," "Lipids," and "Central obesity." They explained approximately 60% of the variance in the 11 original variables. Two factors classified as "Obesity" and "Central Obesity" overlapped when FA was performed without rotation. All four factors in FA with Varimax rotation were consistent between Blacks and Whites, between genders and also after excluding type 2 diabetes (T2D) participants. Fasting insulin (INS) associated mainly with obesity and lipids factors. CONCLUSIONS: MetS in the HyperGEN study has a compound phenotype with separate domains for obesity, blood pressure, and lipids. Obesity and its relationship to lipids and insulin is clearly the dominant factor in MetS. Linkage analysis on factor scores for components of MetS, in familial studies such as HyperGEN, can assist in understanding the genetic pathways for MetS and their interactions with the environment, as a first step in identifying the underlying pathophysiological causes of this syndrome.

Effects of smoking, alcohol, exercise, education, and family history on the metabolic syndrome as defined by the ATP III

INTRODUCTION

Although several environmental factors are known to have diverse effects on the development of the metabolic syndrome, few studies have examined their relevance to Asians.

METHODS

We gathered data from 4341 subjects on smoking, alcohol drinking, exercise, family history and education level by a self-administered questionnaire. The components of the metabolic syndrome as defined by the ATP III report were examined.

RESULTS

The multivariate-adjusted odds ratio of hypertriglyceridemia was 1.4 (95% CI 1.0-1.8) and of low HDL-C was 1.9 (95% CI 1.3-2.6) in subjects who smoked more than 20 pack-years compared to nonsmokers. The relative risk of developing the metabolic syndrome in smokers (more than 20 pack-years) was 1.9 (95% CI 1.1-3.7) compared to nonsmokers. Alcohol consumption had a protective effect against low HDL-C (adjusted OR 0.6-0.2). The relative risk of the metabolic syndrome was 1.7 (95% CI 0.9-2.8) for lack of exercise, 1.5 (95% CI 1.1-2.1) for a positive family history and 2.0 (95% CI 1.2-3.4) in those with no or an elementary school education versus university graduation.

CONCLUSION

Since subjects with a low education level and a family history had an elevated risk for the metabolic syndrome and thus for developing cardiovascular disease, particular attention should be paid to these subjects.

Insulin resistance and cardiovascular disease risk factors in children of parents with the insulin resistance (metabolic) syndrome

OBJECTIVE

To evaluate whether children of parents with the insulin resistance syndrome (IRS) themselves have greater insulin resistance and unfavorable patterns of cardiovascular disease (CVD) risk factors.

RESEARCH DESIGN AND METHODS

This cross-sectional study included 220 white and 36 black children aged 11-15 years identified through a school-based blood pressure screening program, along with 378 of their parents. Measures of insulin resistance (glucose disposal per minute per kilogram of lean body mass in a euglycemic-hyperinsulinemic clamp [Mlbm] and fasting insulin), adiposity, and other CVD risk factors were compared in children with and without a parental history of IRS, defined according to the National Cholesterol Education Program Adult Treatment Panel III consensus definition.

RESULTS

Compared with children in whom neither parent had IRS, children who had at least one parent with the syndrome had statistically significantly lower mean Mlbm (12.1 vs. 13.6 mg.kg(-1).min(-1); P=0.04) and higher fasting insulin (geometric means 99 vs. 76 pmol/l; P=0.01) after adjustment for sex, race, age, and Tanner stage. Mean BMI, waist circumference, waist-to-hip ratio, triceps and subscapular skinfolds, and percentage of body fat were also significantly higher in children of an affected parent, but there were no significant differences in lipid or blood pressure levels between the two groups.

CONCLUSIONS

Insulin resistance and obesity may be the earliest manifestations of IRS in children with a parental history of the syndrome.

Familial aggregation of components of the multiple metabolic syndrome in the Framingham Heart and Offspring Cohorts: Genetic Analysis Workshop Problem 1

Background

The multiple metabolic syndrome is defined by a clustering of risk factors for cardiovascular disease. We sought to evaluate the familial correlations of the components of the syndrome using data from the Framingham Heart Study original and offspring cohorts as provided for the Genetic Analysis Workshop 13. Measures of plasma cholesterol (total and HDL), body mass index (BMI), and systolic blood pressure were used from selected calendar years of exams. Familial correlations were calculated using FCOR in S.A.G.E.

Results

The sibling correlations were relatively high for all measures and exams, from 0.17 for systolic blood pressure to 0.27 for HDL cholesterol. The parent-child correlations were very similar, except for systolic blood pressure. The avuncular correlations were much smaller and the cousin correlations were even smaller. For HDL cholesterol the avuncular correlation was half the sibling correlation and the cousin correlation was half that again. Spousal correlations ranged from 0.07 for systolic blood pressure to 0.34 for BMI. Correlations were somewhat lower from 1984 to 1987 examinations than from 1971 to 1975 examinations, except for spousal correlations for systolic blood pressure and BMI.

Conclusion

The results of the family pair correlations are suggestive of genetic determinants of lipid levels and BMI. These components have been shown to be predictive of cardiovascular disease as well as diabetes. Genes in common with each of the components might also influence development of cardiovascular disease and diabetes, both complex diseases.

The role played by neural crest cells in the development of syndrome X: a hypothesis

This study evaluated the components and the related hormone releasing organs, the mechanism of action of these hormones, and the origins of the cells and organs in a disorder known as metabolic syndrome X, the prevalence of which is rapidly increasing particularly among the adult population of industrial societies. Metabolic syndrome X, involving carbohydrate and lipid metabolism disorders and cardiovascular disorders caused by the release of primary hormones, alpha and beta cells of the islets of Langerhans of pancreas, adrenal gland medulla's chromaffin cells, sympathetic nervous system neurons and ganglia, adenohypophysis, neurohypophysis and hypothalamus, were evaluated for being neuroectodermal and mainly having neural crest origin. Generally the cells, tissues and organs involved are neuroectodermal and especially have neural crest origins; and to conclude, in prevention, diagnosis and treatment of this disorder the priority is the analysis and understanding of the migration, differentiation and adaptation at the target of neural crest cells.

Sex-Specific and Sex-Independent Quantitative Trait Loci for Facets of the Metabolic Syndrome in WOKW Rats

WOKW rats develop a complete metabolic syndrome closely resembling human disease. Since genetic studies using male (WOKW x DA)F2 progeny showed that several independent genetic factors were involved, a polygenic basis for the syndrome in WOKW was assumed. However, because the metabolic syndrome in human clearly demonstrates sex differences, we have extended our study to include both male and female (WOKW x DA)F2 progeny in a genome-wide scan. Male- or female-specific quantitative trait loci (QTLs) were mapped for body weight, body mass index, adiposity index and serum insulin on chromosomes 1 and 5, serum triglycerides on chromosomes 4, 7, 11, and 16, serum total and high density lipoprotein cholesterol on chromosomes 3, 4, 5, 10, and 17, and serum leptin on chromosomes 8 and 16 as well as blood glucose and glucose tolerance (AUC) on chromosomes 3, 4 and 17. QTLs for both, males and females were only found for body weight on chromosome 1 and for serum total cholesterol on chromosome 3 and 10. These findings clearly demonstrate that there are sex-specific and sex-independent QTLs for facets of the metabolic syndrome in WOKW rats.