The Most Important Predictors of Metabolic Syndrome Persistence after 10-year Follow-Up: YHHP Study

BACKGROUND

Metabolic syndrome (MetS) is one of the world's largest health epidemics, and its management is a major challenge worldwide. The aim of this 10-year follow-up study was to assess the most important predictors of MetS persistence among an Iranian adult population.

METHODS

In this cohort study, 887 out of 2000 participants with MetS aged 20-74 years in the central part of Iran were followed-up for about 10 years from 2005-2006 to 2015-2016. MetS was defined based on the criteria of NCEP-ATP III adopted for the Iranian population. Cox proportional hazards regression was conducted to evaluate the predictors of MetS persistence in crude- and multivariate-adjusted models.

RESULTS

Our analyses showed that 648 out of 887 participants (73%) completed the follow-up and 565 (87.2%) of them had persistence of MetS after 10-year follow-up. There was a significant association between age, weight, body mass index, triglyceride, and waist circumference in participants who had MetS compared to those without MetS after 10-year follow-up (P < 0.05). There was a direct association between increases in the mean changes of systolic/diastolic blood pressure, waist circumference, and low HDL-C and risk of MetS persistence after adjusting the model for sex and age in the total population (P trend < 0.05). The trends were the same for women except in diastolic blood pressure. After adjustment for potential confounders, the risk of MetS persistence in men was significantly higher than women (HR = 1.98, 95% CI: 1.38-2.85, Ptrend = 0.001).

CONCLUSIONS

Most of the risk factors of MetS were positively associated with persistence of MetS. Therefore, modification of lifestyle is recommended to reduce MetS.

Effect of dietary habits on the risk of metabolic syndrome: Yazd Healthy Heart Project

Objective

Metabolic syndrome (MetS) refers to a group of risk factors that increase the risk of cardiovascular mortality and morbidity. Dietary habits are among the most important risk factors for MetS. The current study aimed at assessing the effect of dietary habits on the risk of MetS in a 10-year follow-up study in central Iran.

Design

Cohort study.

Setting

Yazd, Iran.

Subjects

Participants aged 20–74 years without any history of MetS, who were originally recruited for Yazd Healthy Heart Project (YHHP) during 2005–2006, were revisited during 2015–2016. At phase I of YHHP, demographic data, anthropometric measurements, five components of MetS, biochemical tests and dietary habits were evaluated; and the same data were collected in phase II.

Results

A total of 1092 participants were eligible to be included in the present study. After follow-up, the 10-year cumulative incidence of MetS was 56·1 %. After adjustment for potential confounders, increased risk of MetS (hazard ratio; 95 % CI) was found in those who did not try to control their body weight (1·57; 1·06, 2·35), did not usually eat salad (1·91; 1·22, 3·00) and added salt to their food (1·57, 1·06, 2·33). These associations were stronger in men than in the total population after subgroup analysis, but were not present in women.

Conclusions

Dietary habits affect the risk of MetS in the Iranian population. Lifestyle interventions are needed to improve dietary habits to reduce the risk of MetS. Future studies are highly recommended to confirm our results in other populations.

The correlation between serum free thyroxine and regression of dyslipidemia in adult males: A 4.5-year prospective study

Elevated free thyroxine (FT4) levels may play a protective role in development of dyslipidemia. However, few prospective studies have been performed to definite the effects of thyroid hormones on the improvement of dyslipidemia and its components. Thus, this study aims to clarify the association between thyroid hormones within normal range and reversal of dyslipidemia in the absence of intervention.A prospective analysis including 134 adult males was performed between 2010 and 2014. Anthropometric parameters, thyroid function, and lipid profile were measured at baseline and during follow-up. Logistic regression and receiver operating characteristic (ROC) analysis were conducted to identify the variables in forecasting the reversal of dyslipidemia and its components.During 4.5-year follow-up, 36.6% (49/134) patients resolved their dyslipidemia status without drug intervention. Compared with the continuous dyslipidemia group, subjects in reversal group had elevated FT4 and high-density lipoprotein cholesterol (HDL-C) levels, as well as decreased total cholesterol (TC), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C) levels at baseline. Furthermore, baseline FT4 is negatively associated with the change percentages of TG (r = -0.286, P = .001), while positively associated with HDL-C (r = 0.227, P = .008). However, no correlation of lipid profile change percentages with FT3 and TSH were observed. Furthermore, the improving effects of baseline FT4 on dyslipidemia, high TG, and low HDL-C status were still observed after multivariable adjustment. In ROC analysis, areas under curve (AUCs) for FT4 in predicting the reversal of dyslipidemia, high TG, and low HDL-C were 0.666, 0.643, and 0.702, respectively (P = .001 for dyslipidemia, .018 for high TG, and .001 for low HDL-C).Higher FT4 value within normal range may ameliorate the dyslipidemia, especially high TG and low HDL-C status, in males without drug intervention. This suggests that a more flexible lipid-lowering therapy may be appropriate for patients with high-normal FT4.

A prospective study of serum adiponectin and regression of metabolic syndrome: The ARIRANG study

Increased serum adiponectin levels may play a protective role in metabolic syndrome. However, few prospective studies have examined the effect of serum adiponectin in the improvement of metabolic components in subjects with metabolic syndrome. We investigated the association of serum adiponectin levels with the regression of metabolic syndrome in a population-based longitudinal study. A total of 1308 adults (575 men and 733 women) with metabolic syndrome at baseline were examined and followed. Baseline serum adiponectin concentrations were measured by radioimmunoassay. During an average of 2.6 years of follow-up, metabolic syndrome had disappeared in 184 men (29.8%) and 235 women (32.1%). In multivariable adjusted models, the odds ratio (95% confidence interval) for regression of metabolic syndrome comparing the highest to the lowest quartiles of adiponectin levels was 0.93 (0.56-1.53) in men and 2.48 (1.54-4.01) in women. Increased serum adiponectin is a predictor for the regression of metabolic syndrome in women. Adiponectin may have potential therapeutic applications in metabolic disease.