Does a diagnosis of the metabolic syndrome provide additional prediction of cardiovascular disease and total mortality in the elderly? The Dubbo Study

Gender differences in the impact of metabolic syndrome components on mortality in older people: A systematic review and meta-analysis

BACKGROUND AND AIMS

The influence of metabolic syndrome (MetS) on mortality may be influenced by age- and gender-related changes affecting the impact of individual MetS components. We investigated gender differences in the association between MetS components and mortality in community-dwelling older adults.

METHODS AND RESULTS

Prospective studies were identified through a systematic literature review up to June 2019. Random-effect meta-analyses were run to estimate the pooled relative risk (RR) and 95% confidence intervals (95% CI) of all-cause and cardiovascular (CV) mortality associated with the presence of MetS components (abdominal obesity, high triglycerides, low HDL cholesterol, high fasting glycemia, and high blood pressure) in older men and women. Meta-analyses considering all-cause (103,859 individuals, 48,830 men, 55,029 women; 10 studies) and CV mortality (94,965 individuals, 44,699 men, 50,266 women; 8 studies) did not reveal any significant association for abdominal obesity and high triglycerides in either gender. Low HDL was associated with increased all-cause (RR = 1.16, 95% CI: 1.02-1.32) and CV mortality (RR = 1.34, 95% CI: 1.03-1.74) among women, while weaker results were found for men. High fasting glycemia was associated with higher all-cause mortality in older women (RR = 1.35, 95% CI: 1.22-1.50) more than in older men (RR = 1.21, 95% CI: 1.13-1.30), and CV mortality only in the former (RR = 1.36, 95% CI: 1.04-1.78). Elevated blood pressure was associated with increased all-cause mortality (RR = 1.16, 95% CI: 1.03-1.32) and showed marginal significant results for CV death only among women.

CONCLUSIONS

The impact of MetS components on mortality in older people present some gender differences, with low HDL cholesterol, hyperglycemia, and elevated blood pressure being more strongly associated to all-cause and CV mortality in women.

New Simplified Diagnostic Decision Trees for the Detention of Metabolic Syndrome in the Elderly

BACKGROUND

A new simplified method for the detention of metabolic syndrome (MetS) is proposed using two variables (anthropometric and minimally invasive).

METHODS

A study of MetS prevalence was made on a sample of 361 older people. The anthropometric variables analyzed were: blood pressure, body mass index, waist circumference (WC), waist-height ratio, body fat percentage, and waist-hip ratio. A crude and adjusted binary logistic regression was performed, and receiver operating characteristic curves were obtained for determining the predictive capacity of those variables. For the new detection method, decision trees were employed using automatic detection by interaction through Chi-square.

RESULTS

The prevalence of the MetS was of 43.7%. The final decision trees uses WC and basal glucose (BG), whose cutoff values were: for men, WC ≥ 102.5 cm and BG > 98 mg/dL (sensitivity = 67.1%, specificity = 90.3%, positive predictive value = 85%, validity index = 79.9%); and for women, WC ≥ 92.5 cm and BG ≥ 97 mg/dL (sensitivity = 65.9%, specificity = 92.7%, positive predictive value = 87.1%, validity index = 81.3%). In older women the best predictive value of MetS was a WC of 92.5 cm.

CONCLUSIONS

It is possible to make a simplified diagnosis of MetS in older people using the WC and basal capillary glucose, with a high diagnostic accuracy and whose use could be recommended in the resource-poor health areas. A new cutting point in older women for the WC should be valued.

Metabolic syndrome, its components and mortality: A population-based study

Background: The association between Metabolic syndrome (MetS), its components and mortality has not been clearly established. The aim of this study was to determine the effects of Mets and its components on all cause and cause-specific mortality and to examine whether MetS or its components were better predictors of mortality.

Methods: In this retrospective cohort study, we used data from the Zanjan Healthy Heart Study performed in 2003 on 4000 persons. Based on the definitions provided by the NCEP- ATPIII, 1051 participants with MetS and 1219 with none or one of its components at study entry were enrolled. Information regarding the mortality and morbidity of 502 participants with MetS and 523 controls was collected in 2013 by telephone. Cause of death was defined as Cardio-Vascular Disease (CVD) or non-CVD. Data were analyzed using the Cox Proportional Hazards model to estimate the hazard ratios predicted by MetS and its individual components.

Results: The median duration of follow-up was 104±10.7 months. Thirty-five deaths occurred, including 18 cardiovascular deaths. The proportion of those with CVD, hypertension, diabetes or hospital stay was statistically higher in MetS patients than controls (p<0.0001). The hazard ratios of all-cause and cardiovascular mortality for those with MetS were 1.75 (%95CI: 0.88-3.47) and 3.66 (%95CI: 1.2-11.1) higher than controls, respectively. Among the components of MetS, only hypertension predicted a higher risk of all-cause and CVD mortality after adjusting for age and sex.

Conclusion: The results of this study indicated that MetS was associated with a higher risk of CVD mortality, morbidity, and hospital stay. Among the components of MetS, the association of hypertension was stronger compared to MetS as a whole. Therefore, this study confirms that MetS is a risk factor for CVD mortality, but not beyond the risk associated with its individual components.

Association of metabolic syndrome and its components with all-cause and cardiovascular mortality in the elderly: A meta-analysis of prospective cohort studies

There is increasing evidence regarding the relationship between metabolic syndrome and mortality. However, previous research examining metabolic syndrome and mortality in older populations has produced mixed results. In addition, there is a clear need to identify and manage individual components of metabolic syndrome to decrease cardiovascular disease (CVD) mortality. In this meta-analysis, we searched the MEDLINE databases using PubMed, Cochrane Library, and EMBASE databases. Based on 20 prospective cohort studies, metabolic syndrome was associated with a higher risk of all-cause mortality [relative risk (RR), 1.23; 95% confidence interval (CI), 1.15-1.32; I = 55.9%] and CVD mortality (RR, 1.24; 95% CI, 1.11-1.39; I = 58.1%). The risk estimates of all-cause mortality for single components of metabolic syndrome were significant for higher values of waist circumference or body mass index (RR, 0.94; 95% CI, 0.88-1.00), higher values of blood glucose (RR, 1.19; 95% CI, 1.05-1.34), and lower values of high-density lipoprotein (HDL) cholesterol (RR, 1.11; 95% CI, 1.02-1.21). In the elderly population, metabolic syndrome was associated with an increased risk of all-cause and CVD mortality. Among the individual components of metabolic syndrome, increased blood glucose and HDL cholesterol levels were significantly associated with increased mortality. However, older obese or overweight individuals may have a decreased mortality risk. Thus, the findings of the current meta-analysis raise questions about the utility of the definition of metabolic syndrome in predicting all-cause mortality and CVD mortality in the elderly population.

Metabolic Syndrome and Cardiovascular Risk in Elderly Treated Hypertensive Patients

BACKGROUND

The independent prognostic significance of the metabolic syndrome (MetS) in the elderly is not yet clear. We investigated the association between MetS and cardiovascular risk (composite endpoint of stroke and coronary events) in elderly treated hypertensive patients.

METHODS

Cardiovascular outcome was evaluated in 1,191 elderly treated hypertensive patients (≥60 years). Among them, 578 (48.5%) had MetS according to a modified joint interim statement definition (body mass index in place of waist circumference).

RESULTS

During the follow-up (9.1±4.9 years, range 0.4-20 years), 139 strokes and 120 coronary events occurred. In univariate analysis, patients with MetS had higher risk of the composite endpoint (hazard ratio (HR) 1.322, 95% confidence interval (CI) 1.035-1.688, P < 0.05). Among the single components of MetS, only blood pressure (BP) level and impaired fasting glucose/diabetes were significantly associated with increased cardiovascular risk. After adjustment for age, previous events, estimated glomerular filtration rate (eGFR), left ventricular (LV) hypertrophy and left atrial (LA) enlargement, the prognostic relevance of MetS was attenuated (HR 1.245, 95% CI 0.974-1.591, P = 0.08). After further adjustment for the above-mentioned variables and ambulatory BP parameters and impaired fasting glucose/diabetes, Cox regression analysis showed that MetS was not independently associated with increased cardiovascular risk (HR 1.090, 95% CI 0.805-1.475, P = 0.58).

CONCLUSIONS

In elderly treated hypertensive patients, MetS is associated with increased cardiovascular risk, but not independently of BP and glucose levels and of organ damage.

Optimal body fat percentage cut-offs for obesity in Chinese adults

Obesity results in an increased risk of metabolic syndrome (MetS) and Type 2 diabetes (T2DM). Body fat percentage (BF%) is a common index of body composition. The aim of the present study was to determine the optimal BF% cut-offs for obesity to predict MetS and T2DM in Chinese adults. The baseline study group comprised 3916 Chinese adults (age 30-70 years of age); 2033 subjects without MetS or T2DM were followed up for a maximum of 5.5 years. The BF% was estimated using bioelectrical impedance analysis. Optimal BF% cut-offs were analysed by receiver operating characteristic (ROC) curves. Binary logistic regression analysis was performed to measure the association between obesity at baseline defined by BF% and newly developed MetS and T2DM. Mean BF% levels were lower in men than in women (23.9 ± 6.1% vs 33.5 ± 7.1%, respectively; P < 0.01). For men, the optimal BF% cut-offs for the prediction of MetS and T2DM were 25.45% and 26.65%, respectively; for women, the corresponding values were 34.95% and 36.55%. Subjects with high BF% (≥ 25% in men; ≥ 35% in women) had higher risks of incident MetS or T2DM than those with low BF% (< 25% in men; < 35% in women). The relative risks were 3.43 (95% confidence intervals (CI) 2.59-4.54) and 2.92 (95% CI 1.85-4.60), respectively. The optimal BF% cut-offs for obesity for the prediction of MetS and T2DM in Chinese men and women were around 25% and 35%, respectively.

Metabolic syndrome and all-cause mortality in older men and women

BACKGROUND

Prevalence of metabolic syndrome (MetS) increases with age, but its association with all-cause mortality in older persons remains uncertain. This study investigated the association of all-cause mortality with MetS and its individual components in older men and women.

METHODS

A total of 917 men and 1043 women aged 65 years and older from two Italian population-based cohorts were included in the study. MetS was defined according to four different definitions: National Cholesterol Education Program (NCEP), NCEP revised according to the American Heart Association and National Heart Lung Blood Institute (NCEP-R), International Diabetes Organization (IDF) and Joint Interim Statement (JIS). All of these definitions include abdominal obesity, hyperglycaemia, hypertriglyceridaemia, low high-density lipoprotein cholesterol and hypertension. Hazard Ratios (HR) and their corresponding 95% confidence interval (95%CI) estimated from multivariable-adjusted Cox regression models were used to investigate the associations of all-cause mortality with baseline MetS status and individual MetS components.

RESULTS

After 6·5 ± 1·8 years of follow-up, there were 179 deaths among women and 193 among men. Mortality risk was increased in women with MetS by any definition, regardless of individual components, but limited to age 70-79 years (NCEP, HR = 2·02, 95%CI, 1·16-3·53; NCEP-R, HR = 2·51, 95%CI, 1·45-4·34; IDF, HR = 2·16, 95%CI, 1·26-3·72; JIS, HR = 2·16, 95%CI, 1·26-3·72). Mortality risk of men was associated with hypertriglyceridaemia below age 70 years (HR = 2·50, 95%CI, 1·19-5·25), but unrelated to MetS status.

CONCLUSIONS

Metabolic Syndrome is associated with all-cause mortality in older women but not in men. The association, however, is limited to a narrow age range.

Metabolic syndrome influencing infarct size and heart failure in patients with acute coronary syndrome: does gender matter?

Metabolic syndrome (MetS) is the occurrence of diabetes mellitus/glucose intolerance, arterial hypertension, central obesity, dyslipidemia, and microalbuminuria in the same patient (definition by WHO). Presence of metabolic syndrome is associated with larger myocardial infarction size and complications following acute myocardial infarction. Two hundred and thirty patients with acute coronary syndromes were analyzed. Those with MetS (n=141) included patients with diabetes mellitus/glucose intolerance and at least two of the following criteria: hypertension, hypertriglyceridemia/low HDL cholesterol, android obesity/body mass index (BMI) ≥ 30, or microalbuminuria. Control group did not meet criteria for MetS. Presence of heart failure was assigned according to Killip classification. The MetS group had larger myocardial infarction size determined by peak creatine-kinase (CK) (1484±1354 vs. 981±890, p = 0.003) and CK MB (141±117 vs. 95±78, p = 0.002). While in non-MetS group males had larger myocardial infarction than females, in MetS group females had larger myocardial infarction than males. Cardiac failure occurred more in MetS group of patients, again was more prominent in females. Occurrence of metabolic syndrome in acute coronary syndrome patients predisposes to larger myocardial infarction size, more on the account of female patients having MetS. MetS, again particularly in females, predisposes to higher chance of having heart failure during acute coronary syndrome. Recognizing the female group with MetS as of higher risk for large myocardial infarction and heart failure leads us to pay special attention on this patient population.

Is prediction of cardiovascular disease and all-cause mortality genuinely driven by the metabolic syndrome, and independently from its component variables? The Dubbo study

BACKGROUND

The Metabolic Syndrome (MetS) predicts an increased risk of cardiovascular disease and all-cause mortality. Is this prediction genuinely driven by the syndrome and independently from its component variables?

METHODS

A longitudinal cohort study in Dubbo, Australia of 2805 men and women ≥60 years followed for 16 years from 1988. Cox proportional hazards models were calculated for coronary heart disease (CHD), ischaemic stroke and all-cause mortality with MetS as an independent variable. Separate models included the MetS variable, with or without the presence of one of its five component variables.

RESULTS

MetS was present in 33% of subjects. Obesity was present in 43% of those with MetS, high blood pressure in 99%, elevated triglycerides in 83%, low HDL-C in 75% and glycaemia in 48%. With respect to CHD and all-cause mortality, prediction by MetS was similar in the presence or absence of individual component factors (e.g. hazard ratio (95% CI) for CHD by MetS when low HDL-C present 1.60(1.39-1.84) and 1.67(1.37-2.04) when low HDL-C absent). With stroke, prediction by MetS was lost in the absence of elevated triglycerides or glycaemia factors (e.g. hazard ratio for stroke by MetS when glycaemia present 1.59(1.24-2.05) and 1.08(0.82-1.42) when glycaemia absent).

CONCLUSIONS

The findings suggest that prediction of CHD and all-cause mortality is genuinely driven by the MetS and independently of its component variables. Prediction of ischaemic stroke is more complex, with some components providing prediction independently from the MetS.

Resistin level is positively correlated with thrombotic complications in Southern Chinese metabolic syndrome patients

BACKGROUND

The metabolic syndrome (MetS) has been found to be closely related with thrombotic diseases. The mechanism, however, is far from elucidated.

AIM

This study was designed to investigate the relationship between endogenous resistin and thrombosis mediating factors, as well as its potential effects on the gene expression of cardiovascular disease biomarkers.

METHODS

Ninety patients satisfied the MetS criteria, and 55 healthy subjects were recruited as part of a single-center clinical study. Plasma levels of resistin, tissue factor (TF), tissue factor pathway inhibitor (TFPI), tissue plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1) were measured by enzymelinked immunosorbent assays. The effect of resistin on the expression of cardiovascular disease biomarkers in human umbilical vein endothelial cells (HUVEC) was assayed by gene microarray.

RESULTS

1) The average levels of resistin in MetS patients with or without acute myocardial or cerebral infarction were significantly higher than those of the controls. 2) The TF and TFPI increase was higher in MetS with infarction patients than in MetS patients. 3) In MetS with infarction patients, resistin was positively correlated with TF and PAI-1 (r=0.313, p=0.008; r=0.401, p=0.002, respectively). 4) In HUVEC, the microarray showed that apolipoprotein C-I, ACE, tumor necrosis factor receptor superfamily member 1A (TNFRSF1A) and member 5 (CD40) genes expression were dramatically increased by resistin.

CONCLUSION

In patients with MetS, resistin is strongly associated with hypercoagulative and hypofibrinolitic activities. Moreover, resistin may induce thrombotic complications via mediating the lipoprotein metabolism and stimulating inflammation.

"The metabolic syndrome... is dead": these reports are an exaggeration

The debates continue over the validity of the metabolic syndrome concept. The continuous increment of the obesity pandemic is almost worldwide paralleled by rising rates of metabolic syndrome prevalence. Then, it seems obvious that these debates drove the need for further investigations as well as a deeper cooperation between relevant national and international organizations regarding the issue. Instead, part of the scientific community elected to totally "dismiss" the concept of the metabolic syndrome. Meanwhile, the best available evidence from three consecutive large meta-analyses has systematically shown that people with metabolic syndrome are at increased risk of cardiovascular events. The most recent and largest of them included near one million patients (total n = 951,083). The investigators concluded that the metabolic syndrome is associated with a 2-fold increase in cardiovascular outcomes and a 1.5-fold increase in all-cause mortality rates. One of the ways to hit the metabolic syndrome is an utterly simplistic view on this concept as a predictive tool only. Of course, the presence of the metabolic syndrome possesses a definite predictive value, but first of all it is a widely accepted concept regarding a biological condition based on the complex and interrelated pathophysiological mechanisms starting from excess central adiposity and insulin resistance. Therefore, it is completely unfair to compare it with statistically constructed predictive tools, including stronger prognostic variables even unrelated to each other from the biological point of view. For example, in the criteria for metabolic syndrome (in contrast to Framingham score) age and cholesterol--presumably low density lipoprotein-cholesterol (LDL-C)--levels are not included, as well as a variety of strong predictors used in other risk-stratification scores: previous myocardial infarction, heart failure, smoking, family history, etc. However, the metabolic syndrome identifies additional important residual vascular risk mainly associated with insulin resistance and atherogenic dyslipidemia (low high density lipoprotein-cholesterol (HDL-C), high triglycerides, small, dense LDL-C). Therefore, the metabolic syndrome could be a useful additional contributor in estimation of global cardiovascular risk beyond age, high LDL-C or other standard risk factors. The components of the metabolic syndrome have partially overlapping mechanisms of pathogenic actions mediated through common metabolic pathways. Therefore their total combined effect could be less than the summed of the individual effects. The concept that the metabolic syndrome is a consequence of obesity and insulin resistance, provides a useful "life-style changes" approach for prevention and treatment: caloric restriction, weight-loss and increased physical activity. The next step could theoretically be pharmacological interventions such as metformin, acarbose, fibrates, weight-loss drugs (currently only orlistat is practically available) and perhaps glucagon-like peptide-1 agonists. A third step should probably be kept for bariatric surgery.

Physical Versus Mental Predictors of Mortality Among the Old-Old in Israel: The CALAS Study

When risk factors are examined concurrently, they tend to show mixed results in predicting mortality among the old-old. The purpose of this study was to compare a set of physical predictors with a set of mental predictors, all considered as most common and predictive in the literature, to assess their relative dominance in predicting mortality at old-old age. Based on Baltes’s incomplete architecture model and the disablement process, the authors postulated that physical predictors of mortality would diminish the impact of mental predictors of mortality. The database used for this study was the multidimensional survey of the Cross-Sectional and Longitudinal Aging Study conducted from 1989 to 1992 with a follow-up of mortality after 10 years. Participants ( N = 1,369) were drawn from a national sample of the Jewish Israeli population aged 75 to 94. The mean age of the sample was 83.52 ( SD = 5.42). Results of hierarchical Cox regression models showed that besides sociodemographic effects (mainly age, gender, and marital status), physical disability, physician visits, and medication consumption predicted mortality. Mental predictors (cognitive impairment and life evaluation) lost their predictive power when the physical predictors were introduced. Hence, biological and physical risk factors predominated over mental risk factors when examining prediction of mortality among the old-old age population.

Estado nutricional e sua associação com risco cardiovascular e síndrome metabólica em idosos

OBJETIVO: Caracterizar o estado nutricional de uma população de idosos e verificar sua associação com fatores de risco cardiovascular e síndrome metabólica. MÉTODOS: Foram avaliados o estado nutricional e prevalências de fatores de risco cardiovascular de síndrome metabólica em amostra de idosos em município da região central do Rio Grande do Sul. O estado nutricional foi determinado por meio de índice de massa corporal, conforme classificação de Lipschitz/1994. O diagnóstico de síndrome metabólica foi obtido por meio dos critérios da International Diabetes Federation. RESULTADOS: Entre os idosos avaliados, a prevalência de excesso de peso foi de 42% entre os homens e de 50% entre as mulheres. As prevalências de hipertensão arterial sistêmica, diabetes mellitus, síndrome metabólica, obesidade central, lipoproteína de alta densidade - colesterol baixo e triglicerídeos elevados foram maiores naqueles com excesso de peso de ambos os sexos. Usando como referência os com estado nutricional normal, os portadores de excesso de peso apresentaram aumento no risco de hipertensão arterial sistêmica, diabetes mellitus e síndrome metabólica, com razão de chances de, respectivamente, 3,3 (IC95%: 1,7 a 6,4), 3,3 (IC95%: 1,48 a 7,11) e 6,9 (IC95%: 3,2 a 14,6), enquanto aqueles com magreza tiveram tendência à razão de chances reduzidas para essas doenças. CONCLUSÃO: As razões de chances de apresentar hipertensão arterial sistêmica, diabetes mellitus e síndrome metabólica na população de idosos da pesquisa estão associadas ao estado nutricional definido pelo índice de massa corporal, sendo progressivamente maiores naqueles com excesso de peso e menores nos com magreza, independente de gênero e idade.

The metabolic syndrome adds utility to the prediction of mortality over its components: The Vietnam Experience Study

BACKGROUND

The metabolic syndrome increases mortality risk. However, as "non-affected" individuals may still have up to two risk factors, the utility of using three or more components to identify the syndrome, and its predictive advantage over individual components have yet to be determined.

METHODS

Participants, male Vietnam-era veterans (n=4265) from the USA, were followed-up from 1985/1986 for 14.7 years (61,498 person-years), and all-cause and cardiovascular disease deaths collated. Cox's proportional-hazards regression was used to assess the effect of the metabolic syndrome and its components on mortality adjusting for a wide range of potential confounders.

RESULTS

At baseline, 752 participants (17.9%) were identified as having metabolic syndrome. There were 231 (5.5%) deaths from all-causes, with 60 from cardiovascular disease. After adjustment for a range of covariates, the metabolic syndrome increased the risk of all-cause, HR 2.03, 95%CI 1.52, 2.71, and cardiovascular disease mortality, HR 1.92, 95%CI 1.10, 3.36. Risk increased dose-dependently with increasing numbers of components. The increased risk from possessing only one or two components was not statistically significant. The adjusted risk for four or more components was greater than for only three components for both all-cause, HR 2.30, 95%CI 1.45, 3.66 vs. HR 1.70, 95%CI 1.11, 2.61, and cardiovascular disease mortality, HR 3.34, 95%CI 1.19, 9.37 vs. HR 2.81, 95%CI 1.07, 7.35. The syndrome was more informative than the individual components for all-cause mortality, but could not be assessed for cardiovascular disease mortality due to multicollinearity. Hyperglycaemia was the individual strongest parameter associated with mortality.

CONCLUSIONS

The metabolic syndrome is informative in predicting mortality, with risk increasing as the number of components increase above the threshold required for diagnosis.

Inverse associations between muscle mass, strength, and the metabolic syndrome

The metabolic syndrome (MetS) is a clustering of individual cardiovascular disease risk factors, which doubles the risk of early mortality. The authors' aimed to determine the prevalence and population attributable risk (PAR%) of the MetS among men according to demographic, physical, and lifestyle risk factors. A cross-sectional study was conducted in 1195 men in the Florey Adelaide Male Ageing Study, a regionally representative cohort of Australian men aged 35 to 81 years conducted in 2002-2005 (response rate, 45.1%). Prevalent MetS was determined according to the Adult Treatment Panel III (ATPIII) and International Diabetes Federation (IDF) classifications; and an extensive list of demographic, physical (including muscle strength, body composition by dual-energy x-ray absorptiometry, sex hormones), and lifestyle factors was accounted for. Prevalence estimates were 37.7% and 41.8% for ATPIII and IDF classifications. Odds ratios for present MetS were determined using multiple-adjusted logistic regression. Odds for present ATPIII MetS decreased (in order of importance) for lower insulin and increased for lower muscle mass, lower strength, and 3+ medical conditions. Odds for present IDF MetS decreased for lower insulin and increased for lower muscle mass, strength, and sex hormone-binding globulin levels; older age; and being married. Significant PAR% due to lowest insulin, muscle mass, and strength quarters were -44%, 27%, and 17% for the ATPIII Met, and -48%, 31%, and 20% for the IDF MetS. A substantial proportion of MetS cases would have been theoretically prevented if prior exposure to low muscle mass and strength were eradicated (PAR% ranged from 14% to 24%). Findings indicate that insulin resistance is a central abnormality in the MetS and that muscle mass and strength are strong protective factors independent of insulin resistance and abdominal fat accumulation. If confirmed prospectively, increases in muscle mass and strength needed to prevent a substantial proportion of MetS cases would be achievable with a short-term strength training intervention.

Metabolic syndrome and risk of mortality in middle-aged versus elderly individuals: the Nord-Trøndelag Health Study (HUNT)

AIMS/HYPOTHESIS

Recent reviews indicate that the metabolic syndrome is a risk factor for cardiovascular disease and mortality, but evidence is scarce in elderly individuals. We therefore examined the relationship between the metabolic syndrome and mortality rates among individuals aged 40-59, 60-74 and 75-89 years. We also examined whether the syndrome was associated with mortality rates over and above the Framingham risk score.

METHODS

We studied prospectively 6,748 men and women who participated in the Nord-Trøndelag Health Study, Norway, from 1995 to 1997 (HUNT 2) and defined the metabolic syndrome by the International Diabetes Federation criteria.

RESULTS

During 53,617 person-years of follow-up (mean per person, 7.9 years), 955 individuals died, of whom 585 died from cardiovascular disease. Among individuals who were 40-59 years of age at baseline, the presence of the metabolic syndrome was associated with increased relative risk of cardiovascular and total mortality (age- and sex-adjusted hazard ratios 3.97 [95% CI: 2.00-7.88] and 2.06 [1.35-3.13], respectively, equivalent to population-attributable risks of 20.7 and 14.2%, respectively). The Framingham risk score accounted for less than one-third of the effect of metabolic syndrome on mortality rates. After the age of 60 years, the metabolic syndrome was not associated with increased mortality rates. We found a significant interaction between the metabolic syndrome and age on the relative risk of mortality. Results were confirmed in a sub-sample without cardiovascular disease at baseline.

CONCLUSIONS/INTERPRETATION

The metabolic syndrome is a risk factor for mortality, over and above the Framingham risk score, in middle-aged, but not in elderly individuals.

The metabolic syndrome increases cardiovascular mortality in Taiwanese elderly

BACKGROUND

The prevalence of the metabolic syndrome (MetS) is high among the elderly. However, evidence that mortality increases with MetS is rare. In this study, we investigated the relationship between MetS, cardiovascular disease (CVD) and all cause mortality in the elderly.

MATERIALS AND METHODS

A total 10 547 participants, aged 65 years and older, of baseline cohort were recruited from four nationwide Health Screening Centres in Taiwan from 1998 to 1999. The metabolic syndrome was defined according to the America Heart Association/National Heart Lung Blood Institute definition. Cox proportional hazards regression analyses were used to estimate the relative risks (RRs) of CVD and all cause mortality for those with MetS for up to 8 years of follow-up.

RESULTS

The baseline prevalence of MetS was 50.1% (45.6% in men and 54.4% in women, respectively). A total of 1312 participants died; of these, 300 participants died from CVD. Adjusted for age, gender, smoking, total cholesterol and estimated glomerular filtration rate, the RRs for CVD and all cause mortality among participants with MetS were 1.48 (95% confidence interval = 1.16-1.90) and 1.16 (1.03-1.30), respectively, for participants compared to those without MetS. The mean RRs for CVD, however, ranged from 1.21 to 5.31 among different combinations of MetS components.

CONCLUSION

The elderly with MetS, compared to those without MetS, had a higher CVD and all cause mortality in Taiwan. Furthermore, different combinations of MetS components posed different risks to the mortality, which deserves further research in the future.