Impact of subclinical atherosclerosis on cardiovascular disease events in individuals with metabolic syndrome and diabetes: the multi-ethnic study of atherosclerosis

OBJECTIVE

While metabolic syndrome (MetS) and diabetes confer greater cardiovascular disease (CVD) risk, recent evidence suggests that individuals with these conditions have a wide range of risk. We evaluated whether screening for coronary artery calcium (CAC) and carotid intimal-medial thickness (CIMT) can improve CVD risk stratification over traditional risk factors (RFs) in people with MetS and diabetes.

RESEARCH DESIGN AND METHODS

We assessed CAC and CIMT in 6,603 people aged 45–84 years in the Multi-Ethnic Study of Atherosclerosis (MESA). Cox regression examined the association of CAC and CIMT with coronary heart disease (CHD) and CVD over 6.4 years in MetS and diabetes.

RESULTS

Of the subjects, 1,686 (25%) had MetS but no diabetes and 881 (13%) had diabetes. Annual CHD event rates were 1.0% among MetS and 1.5% for diabetes. Ethnicity and RF-adjusted hazard ratios for CHD for CAC 1–99 to ≥400 vs. 0 in subjects with neither MetS nor diabetes ranged from 2.6 to 9.5; in those with MetS, they ranged from 3.9 to 11.9; and in those with diabetes, they ranged from 2.9 to 6.2 (all P < 0.05 to P < 0.001). Findings were similar for CVD. CAC increased the C-statistic for events (P < 0.001) over RFs and CIMT in each group while CIMT added negligibly to prediction over RFs.

CONCLUSIONS

Individuals with MetS or diabetes have low risks for CHD when CAC or CIMT is not increased. Prediction of CHD and CVD events is improved by CAC more than by CIMT. Screening for CAC or CIMT can stratify risk in people with MetS and diabetes and support the latest recommendations regarding CAC screening in those with diabetes.Individuals with diabetes and/or metabolic syndrome (MetS) are more likely to have coronary heart disease (CHD) (1,2) and a poorer prognosis compared with those without these conditions (3,4). Those with diabetes without prior myocardial infarction (MI) were originally reported to have the same risk of subsequent MI as those without diabetes but before MI (5), suggesting that diabetes is a CHD risk equivalent. However, recently a large meta-analysis showed that those with diabetes without prior MI had a 43% lower risk of developing CHD events compared with those without diabetes but with a previous MI (6). Both coronary artery calcium (CAC) and carotid intimal-medial thicknesses (CIMTs) are increased in those with MetS and diabetes (7–9). Although the incremental value of CAC and CIMT over traditional risk factors (RFs) has been shown in the general population (10,11), thus reclassifying more individuals in a higher risk category (12), the utility of CAC and CIMT in those with diabetes and/or MetS is unclear (13,14), and screening has not been traditionally recommended in those with diabetes, given their status as having a CHD risk equivalent. We examined in the Multi-Ethnic Study of Atherosclerosis (MESA), a prospective population-based study of cardiovascular disease (CVD), whether CAC and CIMT add predictive value for CVD events in MetS and diabetes and if there is a role for these tests in risk stratification of these populations. Our hypothesis was that CAC and CIMT levels would show a wide range in risks in individuals with MetS and diabetes, as in those without these conditions, and that many people with diabetes would not be at customarily assumed CHD risk equivalents.     

Prevalence of clinical and isolated subclinical cardiovascular disease in older adults with glucose disorders: the Cardiovascular Health Study.

OBJECTIVE: Clinical cardiovascular disease (CVD) is highly prevalent among people with diabetes. However, there is little information regarding the prevalence of subclinical CVD and its relation to clinical CVD in diabetes and in the glucose disorders that precede diabetes. RESEARCH DESIGN AND METHODS: Participants in the Cardiovascular Health Study, aged > or = 65 years (n = 5,888), underwent vascular and metabolic testing. Individuals with known disease in the coronary, cerebral, or peripheral circulations were considered to have clinical disease. Those without any clinical disease in whom CVD was detected by ultrasonography, electrocardiography, or ankle arm index in any of the three vascular beds were considered to have isolated subclinical disease. RESULTS: Approximately 30% of the cohort had clinical disease, and approximately 60% of the remainder had isolated subclinical disease. In those with normal glucose status, isolated subclinical disease made up most of the total CVD. With increasing glucose severity, the proportion of total CVD that was clinical disease increased; 75% of men and 66% of women with normal fasting glucose status had either clinical or subclinical CVD. Among those with known diabetes, the prevalence was approximately 88% (odds ratio [OR] 2.46 for men and 4.22 for women, P < 0.0001). There were intermediate prevalences and ORs for those with impaired fasting glucose status and newly diagnosed diabetes. CONCLUSIONS: Isolated subclinical CVD is common among older adults. Glucose disorders are associated with an increased prevalence of total CVD and an increased proportion of clinical disease relative to subclinical disease.     

Vitamin D levels predict all-cause and cardiovascular disease mortality in subjects with the metabolic syndrome: the Ludwigshafen Risk and Cardiovascular Health (LURIC) Study

OBJECTIVE

Optimal vitamin D levels are associated with reduced cardiovascular and all-cause mortality. We investigated whether optimal 25-hydroxyvitamin D (25[OH]D) is protective in individuals with the metabolic syndrome.

RESEARCH DESIGN AND METHODS

The Ludwigshafen Risk and Cardiovascular Health (LURIC) study is a cohort study of subjects referred for coronary angiography between 1997 and 2000, from which 1,801 with the metabolic syndrome were investigated. Mortality was tracked for a median of 7.7 years. Multivariable survival analysis was used to estimate the association between 25(OH)D levels and mortality.

RESULTS

Most subjects (92%) had suboptimal levels of 25(OH)D (<75 nmol/L), with 22.2% being severely deficient (<25 nmol/L). During follow-up, 462 deaths were recorded, 267 (57.8%) of which were cardiovascular in origin. After full adjustment, including the metabolic syndrome components, those with optimal 25(OH)D levels showed a substantial reduction in all-cause (hazard ratio [HR] 0.25 [95% CI 0.13–0.46]) and cardiovascular disease mortality (0.33 [0.16–0.66]) compared with those with severe vitamin D deficiency. For specific cardiovascular disease mortality, there was a strong reduction for sudden death (0.15 [0.04–0.63]) and congestive heart failure (0.24 [0.06–1.04]), but not for myocardial infarction. The reduction in mortality was dose-dependent for each of these causes.

CONCLUSIONS

Optimal 25(OH)D levels substantially lowered all-cause and cardiovascular disease mortality in subjects with the metabolic syndrome. These observations call for interventional studies that test whether vitamin D supplementation provides a useful adjunct in reducing mortality in these subjects.The cluster of cardiovascular risk factors termed the metabolic syndrome is an important determinant of vascular disease (1–4), which is the major cause of morbidity and mortality worldwide. Available pharmacologic and lifestyle interventions have been shown to attenuate the hazard associated with the syndrome and its components (5,6). However, these treatment modalities still fail to normalize risk, and much research effort is therefore dedicated to exploring additional treatment approaches, for which targeting suboptimal vitamin D levels presents a potentially important option.Studies in the U.S. and Europe show that most of the general population have 25-hydroxyvitamin D (25(OH)D) levels below the target level of 75 nmol/L (7,8), with levels being even lower in those with the metabolic syndrome (9). The high prevalence of a poor vitamin D status has gained much public health interest because of its association with cardiovascular disease conditions, including arterial hypertension, diabetes, and the metabolic syndrome. Moreover, prospective studies have shown that low 25(OH)D levels are associated with increased all-cause and cardiovascular mortality (10–13). Whether these associations are causal remains to be explored, but it is often stressed that vitamin D metabolites regulate a very wide range of genes with significance for overall and cardiovascular health (14), making causality a plausible hypothesis.In light of nascent evidence for a protective effect of optimal vitamin D levels, it is perhaps surprising that no studies have specifically addressed whether vitamin D levels predict mortality and cardiovascular events in subjects with the metabolic syndrome. Such data are needed to assess the potential of supplementation studies in this increased-risk population. We therefore studied a large cohort of subjects referred for coronary angiography, focusing our analyses on 1,801 individuals who fulfilled the criteria for the metabolic syndrome.     

Trend in the prevalence of the metabolic syndrome and its impact on cardiovascular disease incidence: the San Antonio Heart Study

OBJECTIVE: With the current obesity epidemic, one would expect a prevalence increase in the metabolic syndrome. Therefore, in the San Antonio Heart Study, a population-based study with worsening obesity, we examined the metabolic syndrome and its effect on incident cardiovascular disease (CVD). RESEARCH DESIGN AND METHODS: We enrolled 5,158 subjects in two cohorts: 1979-1982 and 1984-1988. We reexamined 3,682 (71.4%) subjects in 1987-1990 (cohort 1) and 1991-1996 (cohort 2) and assessed a 7.5-year incidence of CVD in 4,635 (90.0%) participants. We used the metabolic syndrome definition of the National Cholesterol Education Program-Adult Treatment Panel III. RESULTS: At baseline, the metabolic syndrome was less prevalent in cohort 1 than in cohort 2: in men, 20.4 vs. 29.3% (P < 0.001); in women, 16.3 vs. 26.3% (P < 0.001). The prevalence increased in men and women of both Mexican-American and non-Hispanic white ethnic groups between 1979-1982 and 1991-1996 (P for trend <0.001 for each of the groups). There was an excess of incident CVD in cohort 2 relative to cohort 1 (odds ratio 1.37 [95% CI 1.02-1.84]) after adjustment for age, sex, ethnic origin, socioeconomic status, history of CVD, diabetes, total cholesterol, smoking, and family history of heart attack. Further adjustment for the metabolic syndrome reduced this difference (1.26 [0.93-1.71]) because the metabolic syndrome predicted incident CVD (1.58 [1.14-2.18]). CONCLUSIONS: In San Antonio, Texas, an increase in the prevalence of the metabolic syndrome between 1979-1982 and 1984-1988 contributes to explain a higher CVD incidence.     

The metabolic syndrome and cardiovascular disease

The metabolic syndrome, which is very common in the general population, is defined by the clustering of several classic cardiovascular risk factors, such as type 2 diabetes, hypertension, high triglycerides and low high-density lipoprotein cholesterol (HDL). Central obesity and insulin resistance, which are the two underlying disorders of the syndrome, are further risk factors for cardiovascular disease. Moreover, a panel of novel (non-traditional) risk factors are ancillary features of the metabolic syndrome. They include biomarkers of chronic mild inflammation (e.g. C-reactive protein, CRP), increased oxidant stress (e.g. oxidized low density lipoprotein, LDL), thrombophilia (e.g. plasminogen activator inhibitor-1, PAI-1) and endothelial dysfunction (e.g. E-selectin). Therefore, subjects with the metabolic syndrome are potentially at high risk of developing atherosclerosis and clinical cardiovascular events.In recent years several longitudinal studies have confirmed that subjects with the metabolic syndrome present with atherosclerosis and suffer from myocardial infarction and stroke at rates higher than subjects without the syndrome. The risk of cardiovascular disease (CVD) is particularly high in women with the syndrome and in subjects with pre-existing diabetes, CVD and/or high CRP. However, an increased risk is already present in subjects with a cluster of multiple mild abnormalities. The risk related to the metabolic syndrome is definitely higher when subjects affected are compared to subjects free of any metabolic abnormality.     

Inflammation and hemostasis biomarkers and cardiovascular risk in the elderly: the Cardiovascular Health Study

BACKGROUND: There are few studies of inflammation and hemostasis biomarkers and cardiovascular disease risk (CVD) in older adults. OBJECTIVES: To assess multiple biomarkers simultaneously and in combinations for CVD risk assessment in older individuals. PATIENTS/METHODS: Thirteen biomarkers, interleukin-6 (IL-6), C-reactive protein (CRP), D-dimer, fibrinogen, factor VII, factor VIII, leukocyte count (WBC), platelet count, lipoprotein(a), soluble intercellular adhesion molecule-1 (sICAM-1), albumin, homocysteine and uric acid, were correlated with incident CVD in 4510 individuals in the Cardiovascular Health Study. Baseline biomarkers were analyzed as gender-specific SD increments and quintiles in proportional hazards models adjusted for demographics, CVD risk factors and medications. RESULTS: Over 9 years with 1700 CVD events, seven biomarkers were associated with CVD. Adjusted hazard ratios (HRs, 95% CI) per SD increment were 1.16 (1.09, 1.23) for IL-6, 1.16 (1.09, 1.23) for CRP, 1.13 (1.05, 1.21) for D-dimer, 1.17 (1.09, 1.25) for homocysteine, 1.06 (1.00, 1.12) for WBC, 1.06 (1.00, 1.12) for factor VIII, and 1.07 (1.00, 1.13) for lipoprotein(a). Fibrinogen was associated with CVD in men only (HR 1.12, 95% CI 1.04, 1.22) and sICAM-1 in women only (HR 1.16, 95% CI 1.05, 1.27). IL-6 and CRP remained associated with CVD when modeled with WBC. Participants were classified by all combinations of two biomarkers being high or low (IL-6, CRP, WBC, factor VIII, cholesterol/HDL). All were associated with CVD when cholesterol/HDL was low and none when CRP was low. CONCLUSIONS: Seven biomarkers were associated with CVD in older adults, with CRP having some advantages compared with others. Even larger studies are needed to better characterize these associations.     

New-onset diabetes and risk of all-cause and cardiovascular mortality: the Cardiovascular Health Study

OBJECTIVE: Cardiovascular risk associated with new-onset diabetes is not well characterized. We hypothesized that risk of all-cause and cardiovascular mortality would be similar among participants with and without new-onset diabetes in the first years of follow-up and rise over time for new-onset diabetes. RESEARCH DESIGN AND METHODS: The Cardiovascular Health Study (CHS) is a longitudinal study of cardiovascular risk factors in adults aged > or =65 years. We used CHS participants to define a cohort (n = 282) with new-onset diabetes during 11 years of follow-up. New-onset diabetes was defined by initiation of antidiabetes medication or by fasting plasma glucose >125 mg/dl among CHS participants without diabetes at study entry. Three CHS participants without diabetes were matched for age, sex, and race to each participant with new-onset diabetes at the time of diabetes identification (n = 837). Survival analysis provided adjusted hazard ratios (HRs) for all-cause and cardiovascular mortality. RESULTS: During a median of 5.9 years of follow-up, there were 352 deaths, of which 41% were cardiovascular. In adjusted analyses, new-onset diabetes was associated with an HR of 1.9 (95% CI 1.4-2.5) for all-cause and 2.2 (1.4-3.4) for cardiovascular mortality compared with no diabetes. Mortality risks were elevated within 2 years of onset, especially cardiovascular risk (4.3 [95% CI 1.7-10.8]), and did not increase over time. CONCLUSIONS: Our findings indicate that there may be a mortality differential soon after diabetes onset in older adults and suggest that long-term macrovascular damage from atherosclerosis may not be primarily responsible for increased risk.     

Metabolic Syndrome: prevalence and prediction of mortality in elderly individuals

OBJECTIVE: Little is known about the prevalence of the metabolic syndrome among elderly people in Italy, its association with all-cause mortality, and whether measurement of serum C-reactive protein (CRP) and interleukin (IL)-6 affects this association. RESEARCH DESIGN AND METHODS: The baseline prevalence of metabolic syndrome, diagnosed according to the National Cholesterol Education Program (NCEP) criteria, and all-cause mortality at 4 years were recorded in an Italian population-based cohort (981 subjects, 55% women, aged 65-97 years). A Cox model adjusted for sociodemographic, lifestyle, and medical variables was used to investigate 1) whether metabolic syndrome was a predictor of mortality and 2) how the association was affected by baseline high CRP (>3 mg/l) and IL-6 (>1.33 pg/ml). RESULTS: Overall, metabolic syndrome prevalence was 27.2% [95% CI 24.0-30.5] and higher in women (33.3% [28.7-38.0]) than in men (19.6% [15.5-24.2]). During follow-up, 137 deaths occurred. Using the no metabolic syndrome/no high IL-6 group as the reference, mortality was not associated with the metabolic syndrome alone (multivariable-adjusted hazard ratio 1.24 [0.60-2.59]), only weakly associated with high IL-6 alone (1.66 [1.04-2.63]), but strongly associated with the concurrent presence of metabolic syndrome and high IL-6 (3.26 [2.00-5.33]). High CRP was not a mortality predictor (0.83 [0.58-1.20]) nor did it affect the association of the other variables with mortality. CONCLUSIONS: Metabolic syndrome by NCEP criteria is highly prevalent in the Italian elderly population. It is not itself associated with mortality but may improve the usefulness of IL-6 as a mortality predictor in older age.     

Inter-relationships of interleukin-6, cardiovascular risk factors and the metabolic syndrome among older men

OBJECTIVES: Interleukin-6 (IL-6) has been implicated in the development of cardiovascular disease. We have examined the relationship between plasma IL-6 and insulin resistance, and metabolic, inflammatory and hemostatic markers. METHODS: We examined 3490 men aged 60-79 years who were drawn from general practices in 24 British towns. The men were not diabetic and were not taking warfarin. RESULTS: IL-6 was significantly associated with age, body mass index (BMI), waist circumference (WC), cigarette smoking, low physical activity, social class and alcohol intake (U-shaped). IL-6 showed no association with insulin resistance or its other components (blood glucose, triglycerides, blood pressure) except high-density lipoprotein-cholesterol (inversely), and no association with hematocrit, factor (F) VII or adiponectin after adjustment for age and WC. IL-6 was strongly associated with markers of inflammation (C-reactive protein, fibrinogen, white cell count); plasma viscosity; elevated markers of coagulation (fibrin D-dimer, FVIII, FIX); markers of endothelial dysfunction (von Willebrand factor, tissue plasminogen activator); and to a smaller extent with platelet count, APC ratio and gamma glutamyltransferase. Risk of the metabolic syndrome increased significantly with increasing IL-6 but was attenuated after adjustment for BMI. CONCLUSION: IL-6 may have a potential role as a mediator between cardiovascular risk factors and several biological mechanisms for cardiovascular disease.     

The prevalence of the metabolic syndrome among arab americans

OBJECTIVE: To estimate the prevalence of the metabolic syndrome in Arab Americans by age, sex, and BMI and to examine the association between insulin resistance and each of the components of the metabolic syndrome. RESEARCH DESIGN AND METHODS: We studied a representative, cross-sectional, population-based sample of 542 Arab Americans aged 20-75 years. The metabolic syndrome was defined by Adult Treatment Panel III (ATP III) and World Health Organization (WHO) diagnostic criteria. Insulin resistance was estimated by homeostasis model assessment (HOMA-IR). RESULTS: The age-adjusted prevalence of the metabolic syndrome was 23% (95% CI 19-26%) by the ATP III definition and 28% (24-32%) by the WHO definition. Although the prevalence increased significantly with age and BMI in both sexes by both definitions, differences in estimates were noted. With ATP III, the age-specific rates were similar for men and women aged 20-49 years but were significantly higher for women aged >/=50 years. With WHO, rates were higher for men than women aged 20-49 years and similar for those aged >/=50 years. The most common component of the metabolic syndrome in men and women was low HDL cholesterol with the ATP III and the presence of glucose intolerance and HOMA-IR with the WHO. Strong associations between HOMA-IR and individual components of the metabolic syndrome were observed. After fitting a model with HOMA-IR as the outcome, waist circumference, triglyceride level, and fasting plasma glucose level were significantly associated with HOMA-IR. CONCLUSIONS: The metabolic syndrome is common among Arab Americans and is related to modifiable risk factors.     

Association between metabolic syndrome and calcium oxalate stone risk in Chinese individuals: a nomogram prediction model

ObjectiveThis retrospective study explored the association between calcium oxalate (CaOx) stones and metabolic syndrome. It also developed and validated a nomogram to aid in the prediction of CaOx stones.MethodsThis case-control study enrolled 150 patients with CaOx stones and 635 individuals without urolithiasis from October 2016 to October 2018. Student’s t-test, the chi-squared test, and logistic univariate and multivariate regression analyses were used. A nomogram for prediction of CaOx stones was established based on independent associated factors. The concordance index and calibration curves were plotted to determine nomogram accuracy.ResultsFemale sex, age ≥66 years, blood pressure (systolic pressure ≥130 mmHg and/or diastolic pressure ≥85 mmHg), and blood uric acid level independently influenced the risk of CaOx stones, according to multivariate logistic regression analysis; these factors were included in the nomogram. The concordance index was 0.701 (95% confidence interval: 0.658–0.737). The standard curve showed a robust fit with the calibrated predictive curve.ConclusionsFemale sex, age ≥66 years, elevated blood pressure, and blood uric acid level independently influenced the risk of CaOx stones. Our nomogram for the prediction of CaOx stones may provide a clinical basis for the assessment of CaOx stone and facilitate early prevention efforts.     

Systemic hemodynamics in young adults with the metabolic syndrome: The Cardiovascular Risk in Young Finns Study

Abstract

Objective. We conducted the present study to examine associations of three different metabolic syndrome (MetS) definitions and their components to arterial stiffness, systemic vascular resistance, and left ventricular function at population level. In addition, the objective of the study was to examine associations of spontaneous recovery from MetS over 6 years’ follow-up to systemic hemodynamics.

Methods. The study population consisted of 1,741 Finnish young adults (aged 30–45 years) who had complete MetS risk factor and hemodynamic data available at 2007. Associations of spontaneous recovery from MetS to systemic hemodynamics was studied on a subpopulation of 1,391 subjects who had also complete MetS risk factor data available at 2001. Hemodynamic measurements were performed using a whole-body impedance cardiography device.

Results. MetS and increasing number of MetS components were associated with lower stroke index (P < 0.001) and higher systemic vascular resistance index (P < 0.005) and arterial pulse wave velocity (P < 0.005). In MetS persistent group, stroke index was lower (P = 0.024), and pulse wave velocity was higher (P = 0.003) compared to MetS recovery group.

Conclusion. All current MetS definitions identify young adults with altered systemic hemodynamics, and recovery from MetS is associated with a favorable hemodynamic profile.     

Ethnic differences in cardiovascular risk factors in healthy Caucasian and South Asian individuals with the metabolic syndrome

BACKGROUND: The metabolic syndrome is a cluster of atherothrombotic risk factors that are commonly associated with insulin resistance. OBJECTIVES: The aim of this study was to investigate ethnic differences in insulin resistance and non-traditional cardiovascular risk factors in relation to the International Diabetes Federation (IDF) definition of the metabolic syndrome. PATIENTS AND METHODS: A total of 245 healthy South Asians and 245 age- and sex-matched Caucasians were studied. C-reactive protein (CRP), complement C3, plasminogen activator inhibitor-1 (PAI-1) and tissue plasminogen activator (t-PA) were measured and homeostasis model assessment-insulin resistance (HOMA-IR) was calculated from fasting plasma glucose and insulin levels. RESULTS: Fifty Caucasian (20%) and 95 (39%) South Asian subjects had the metabolic syndrome as defined by the IDF. In South Asian subjects, HOMA-IR, CRP, C3, PAI-1 and t-PA were significantly higher in subjects with the metabolic syndrome. In contrast, in Caucasian individuals there was no difference in HOMA-IR or C3 levels and only CRP, PAI-1 and t-PA were higher in subjects with the metabolic syndrome. In a logistic regression model, plasma levels of CRP and PAI-1 were independent predictors of the metabolic syndrome in Caucasians, whereas plasma levels of C3 and t-PA as well as HOMA-IR were independent predictors of the metabolic syndrome in South Asian subjects. CONCLUSIONS: In the cohort of individuals studied, the IDF definition of the metabolic syndrome was associated with insulin resistance in the South Asian but not the Caucasian population. This work also showed ethnic differences in non-traditional cardiovascular risk factors in the presence of the metabolic syndrome.     

Cardiovascular morbidity and mortality of the metabolic syndrome

Cardiovascular disease remains the single leading cause of morbidity and mortality in the United States. The metabolic syndrome has received increased attention in recent years, partly because of the growing prevalence of obesity and its association with cardiovascular disease. This article reviews current evidence from longitudinal observational studies that evaluated the impact of metabolic syndrome on cardiovascular morbidity and mortality in various population subsets. The approach to cardiovascular risk assessment in individuals who have multiple risk factors and the clinical implications of diagnosing the metabolic syndrome are also discussed.     

Occupation-related differences in the prevalence of metabolic syndrome

OBJECTIVE—To investigate the prevalence of metabolic syndrome in the Spanish working population and determine how the prevalence varies according to occupation and sex.RESEARCH DESIGN AND METHODS—This was a cross-sectional study of 259,014 workers (mean age 36.4 years, range [16–74]; 72.9% male) who underwent a routine medical checkup. The Adult Treatment Panel III (2001) definition for metabolic syndrome was used.RESULTS—The prevalence of metabolic syndrome was 11.6% (95% CI 11.5–11.7) in male subjects and 4.1% (4.0–4.2) in female subjects and increased with age. The prevalence of metabolic syndrome varied in the different categories of occupational activity depending on the sex considered. Among female subjects, the age-adjusted prevalence of metabolic syndrome was higher in blue-collar than in white-collar workers, but this difference was not evident among male workers.CONCLUSIONS—The prevalence of metabolic syndrome varies in the different categories of occupational activity in the Spanish working population. This variation also depends on sex.There is little information about the prevalence of metabolic syndrome or its components in workers (1). The overall prevalence of the metabolic syndrome is ∼25% in general populations from the U.S. and Europe, including Spain (1–3). Some studies have shown a sex-specific inverse association between measures of socioeconomic status and the prevalence of the metabolic syndrome (2–4). This study aimed to investigate the prevalence of metabolic syndrome in the Spanish working population and determine whether prevalence differed according to occupational activity and sex.