[Prevalence of metabolic syndrome in Argentina in the last 25 years: systematic review of population observational studies]. / Prevalencia del síndrome metabólico en Argentina en los últimos 25 años: revisión sistemática de estudios observacionales poblacionales.

INTRODUCTION AND AIM: Metabolic syndrome (MS) comprises a set of risk factors for cardiovascular disease and diabetes. Argentina has numerous epidemiological studies on MS, however, there has been no systematic analysis of the prevalence of MS in our population. To estimate the prevalence of MS in the Argentine Republic, a systematic review of observational studies published during the period 1988-2014 was carried out. SEARCH STRATEGY: A bibliographic search was conducted in the MEDLINE (National Library of Medicine), SciELO (Scientific Electronic Library Online) and LILACS (Latin American and Caribbean Health Sciences Literature) databases on studies conducted in Argentina between January 1989 and December 2014. The following search terms were combined in English, Spanish and Portuguese: 'metabolic syndrome', 'insulin resistance', 'dysmetabolic syndrome', 'prevalence', 'epidemiology', and 'Argentina'. SELECTION OF STUDIES: Epidemiological studies based on the adult population of Argentina with specific report of the prevalence of MS (according to the WHO, ATP III or IDF criteria) were included in the analysis. SYNTHESIS RESULTS: In the initial bibliographic search, 400 publications were identified. In the second phase of search, 296 titles and abstracts were excluded. In the third phase, the full text of 104 studies was analyzed. Finally, 6 publications were included in the analysis that reported the prevalence of MS in a total of 10,191 subjects (39.6% male). The average age of the population was 45.2 years. The prevalence of MS (random effects model) was 27.5% (95% CI: 21.3%-34.1%). The prevalence of MS was higher in men than in women (29.4% vs. 27.4%, respectively, P=.02). In order of frequency, the most common components of MS were dyslipidaemia (38.3%), hypertension (33.4%), obesity (32.1%) and diabetes (7.5%). CONCLUSIONS: Our data show that the prevalence of MS is high, which represents a very important public health problem in Argentina.

Use of the triglyceride/high-density lipoprotein cholesterol ratio to identify cardiometabolic risk: impact of obesity?

There is evidence that the plasma concentration ratio of triglyceride (TG)/high-density lipoprotein cholesterol (HDL-C) identifies insulin resistance and increased cardiometabolic risk and outcome in apparently healthy individuals. Since use of the TG/HDL-C ratio to accomplish this task in persons over a wide range of adiposity has not been studied, the ability of previously defined sex-specific TG/HDL-C cut-points to identify increased cardiometabolic risk was evaluated in apparently healthy normal weight, overweight, and obese individuals. Data were analyzed from a population-based study of apparently healthy men (n=416) and women (n=893), subdivided into categories by body mass index (BMI, kg/m2): normal weight (BMI 20.0-24.9), overweight (BMI 25.0-29.9) and obese (BMI 30.0-34.9). The adiposity groups were further stratified on the basis of their TG/HDL-C ratio into groups defined as being either at 'high risk' versus 'low risk' of cardiometabolic disease. Multiple cardiometabolic risk factors were compared between these subgroups, as was their degree of insulin resistance assessed by fasting plasma insulin concentration and homeostasis model assessment of insulin resistance. The proportion of high-risk individuals varied with BMI category, ranging from 14% (normal weight) to 36% (obese). However, within each BMI category high-risk individuals had a significantly more adverse cardiometabolic risk profile. Finally, the adjusted OR of being insulin resistant was significantly greater in those with a high TG/HDL-C ratio in the normal (3.02), overweight (2.86), and obese (2.51) groups. Thus, irrespective of differences in BMI, the TG/HDL-C ratio identified apparently healthy persons with a more adverse cardiometabolic risk profile associated with an increased prevalence of insulin resistance.

Should the first blood pressure reading be discarded?

We evaluated the consequences of excluding the first of three blood pressure (BP) readings in different settings: a random population sample (POS, n=1525), a general practice office (GPO, n=942) and a specialized hypertension center (SHC, n=462). Differences between systolic and diastolic BP (SBP and DBP) estimates obtained including and excluding the first reading were compared and their correlation with ambulatory BP monitoring (ABPM) was estimated. The samples were divided into quartiles according to the difference between the third and the first SBP (3-1ΔSBP). SBP decreased through sequential readings, 3-1ΔSBP was -5.5 ± 9.7 mm Hg (P<0.001), -5.1 ± 10.4 mm Hg (P<0.001) and -6.1 ± 9.3 mm Hg (P<0.001) for POS, GPO and SHC, respectively. However, individuals included in the top quartile of 3-1ΔSBP showed their highest values on the third reading. The mean SBP estimate was significantly higher excluding the first reading (P<0.001), but the differences among both approaches were small (1.5-1.6 mm g). Moreover, the correlation between SBP values including and excluding the first reading and daytime ABPM were comparable (r = 0.69 and 0.68, respectively). Similar results were observed for DBP. In conclusion, our study does not support the notion of discarding the first BP measurement and suggests that it should be measured repeatedly, regardless the first value.

Identifying cardiovascular disease risk and outcome: use of the plasma triglyceride/high-density lipoprotein cholesterol concentration ratio versus metabolic syndrome criteria.

BACKGROUND: Metabolic syndrome (MetS) has been shown to predict both risk and CVD events. We have identified sex-specific values for the triglyceride/high-density lipoprotein cholesterol (TG/HDL-C) ratio associated with an unfavourable cardio-metabolic risk profile, but it is not known whether it also predicts CVD outcome. METHODS: To quantify risk for CVD outcomes associated with a high TG/HDL-C ratio and to compare this risk with that predicted using MetS, a population longitudinal prospective observational study was performed in Rauch City, Buenos Aires, Argentina. In 2003 surveys were performed on a population random sample of 926 inhabitants. In 2012, 527 women and 269 men were surveyed again in search of new CVD events. The first CVD event was the primary endpoint. Relative risks for CVD events between individuals above and below the TG/HDL-C cut-points, and with or without MetS, were estimated using Cox proportional hazard. MAIN OUTCOME: The first CVD event was the primary endpoint. Relative risks for CVD events between individuals above and below the TG/HDL-C cut-points, and with or without MetS, were estimated using Cox proportional hazard. RESULTS: The number of subjects deemed at 'high' CVD risk on the basis of an elevated TG/HDL-C ratio (30%) or having the MetS (35%) was relatively comparable. The unadjusted hazard risk was significantly increased when comparing 'high' versus 'low' risk groups no matter which criteria was used, although it was somewhat higher in those with the MetS (HR = 3.17, 95% CI:1.79-5.60 vs. 2.16, 95% CI:1.24-3.75). However, this difference essentially disappeared when adjusted for sex and age (HR = 2.09, 95% CI:1.18-3.72 vs. 2.01, 95% CI:1.14-3.50 for MetS and TG/HDL-C respectively). CONCLUSIONS: An elevated TG/HDL-C ratio appears to be just as effective as the MetS diagnosis in predicting the development of CVD.