Prehypertension among adults in Great Tunis region (Tunisia): A population-based study.

PURPOSE: The present study aimed to determine the prevalence of prehypertension (preHTN) and its cardiometabolic profile in Tunisians, and to estimate the risk for coronary heart disease (CHD) according to blood pressure status. PATIENTS AND METHOD: This cross-sectional study was conducted in 2004-2005, and used a two-stage cluster sampling method to select a representative sample of the Great Tunis population. A total of 2712 individuals (1228 men and 1484 women), aged 35 to 69 years were included. Definition and classification of hypertension (HTN) was performed according to guidelines from the Joint National Committee on prevention, detection, evaluation and treatment of high blood pressure (JNC-7) report. RESULTS: The prevalence of preHTN and HTN was 56.8% and 25.0% in males, and 43.1% and 36.1% in females, respectively. Subjects with preHTN and those with HTN showed higher prevalence of diabetes, dyslipidemia, obesity and abdominal obesity than the normotensive (NT) group. The metabolic syndrome (MetS) was found in 8.0%, 17.8% and 53.8% of NT, preHT and HTN subjects, respectively. The risk of developing CHD within 10 years, as predicted by the Framingham-Anderson model, was above 15% for 3.9%, 31.1% and 65.0% among NT, preHTN and HTN subjects, respectively. In multivariate analysis, preHTN was associated with age (OR [95% CI], 1.02 [1.01-1.03]; P<0.01), male gender (2.51 [1.89-3.23]; P<0.001), obesity (2.36 [1.71-3.26]; P<0.01), abdominal obesity (1.53 [1.14-2.06]; P<0.01) and smoking (0.70 [0.53-0.92]; P<0.01). CONCLUSION: PreHTN is very common in Tunisians. It is associated with a higher prevalence of cardiometabolic risk factors and confers a higher risk for subsequent CHD. These findings support the recommendations of lifestyle modification for preHTN patients.

The metabolic syndrome: prevalence, main characteristics and association with socio-economic status in adults living in Great Tunis.

AIMS: This study aimed to determine the prevalence of the metabolic syndrome (MetS) and its association with socio-economic status in the population of Great Tunis. METHODS: The study included 2712 subjects (1228 men and 1484 women), aged 35-70 years and living in the Great Tunis region, all of whom were recruited between March 2004 and June 2005. The sample was weighted by using the inverse of the response rate according to governorate, district and gender. The MetS was defined according to the National Cholesterol Education Program-Adult Treatment Panel III. RESULTS: In the studied population, the overall prevalence of the MetS was 31.2%, and it was significantly more frequently seen in women than in men (37.3% vs 23.9%, respectively; P<0.001), as were abdominal obesity (69% vs 21.6%, respectively; P<0.001), high blood pressure (50.3% vs 43.1%, respectively; P<0.001) and low HDL cholesterol (40.6% vs 33.6%, respectively; P<0.001), the most common characteristics of the MetS. Also, the prevalence of the MetS increased with age in both genders, but more so in women. In those aged greater than 55 years, the prevalence of MetS was 56.7% in women and 30.7% in men. An inverse relationship was observed between level of education and prevalence of the MetS in women, with the highest prevalence being in illiterate women and the lowest in those who were university graduates. CONCLUSION: The prevalence of the MetS is markedly high within the population of Great Tunis and especially in women. As these findings predict future increases in cardiovascular disease in these populations, substantial efforts need to be made to fight against obesity and sedentary lifestyles to ameliorate the expected poor health outcomes.

[XbaI polymorphism of apolipoprotein B gene in a Tunisian population: alleles frequencies and relationship with plasma lipid parameters]. / Polymorphisme XbaI du gène de l'apolipoprotéine B dans une population tunisienne: fréquences alléliques et relation avec les paramètres lipidiques plasmatiques.

Apolipoprotein B (Apo B) is a component of chylomicrons, low-density lipoproteins (LDL), very low density lipoproteins (VLDL), and intermediate-density lipoproteins (IDL) and is the ligand for the LDL receptor. Thereby, Apo B plays a central role in lipoprotein metabolism and in maintaining the normal homeostasis of serum cholesterol levels. Several Apo B restriction fragment length polymorphisms (XbaI, EcoRI, MspI) have been reported to be associated with variation in lipid levels, obesity and/or coronary artery disease. To date, no data are available on relationship between XbaI Apo B polymorphism and lipid levels in Tunisian population. Here, we report frequencies of the XbaI polymorphism of the Apo B gene and we assess the effect of this polymorphism on lipid and lipoprotein concentrations in Tunisian population. Blood samples from 296 Tunisian individuals (112 women and 184 men, aged 51.4+/-9.6 years), were analysed for total cholesterol, triglycerides, HDL-cholesterol and apolipoproteins A1 and B. In parallel, genotyping by means of polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) was performed. The XbaI polymorphism was associated with differences in plasma cholesterol (p=0.04), triglyceride (p=0.02) and apolipoprotein A1 (p=0.004), individuals with the genotype X1X1 have the lowest mean levels and those with the genotype X2X2 have the highest, with the individuals heterozygous for the polymorphism having intermediate levels. According to sex, the XbaI polymorphism effect was only observed for triglyceride in men. Thus, the results demonstrate an influence of XbaI polymorphism of Apo B gene on serum total-cholesterol, triglycerides and apolipoprotein A1 concentrations among Tunisian population.

Apolipoprotein B signal peptide polymorphism: distribution and influence on lipid parameters in Tunisian population.

Apolipoprotein B (apo B) is the major protein component of LDL, VLDL and chylomicrons. Numerous polymorphisms of the apolipoprotein B gene have been described. Particularly, the insertion/deletion polymorphism located in the coding part of the signal peptide of apo B, associated with modification of lipid concentrations and the risk of cardiovascular disease, has been reported in the general population. No such study in the Tunisian population has been performed. The aim of our study was to assess the effect of insertion/deletion polymorphism of the apolipoprotein B gene on lipid levels in a sample of the Tunisian population. A total of 458 unrelated subjects (321 men and 137 women) were included. The insertion/deletion polymorphism was determined by electrophoresis on polyacrylamide gels after PCR amplification. The relative frequencies of the Ins and Del alleles were 0.74 and 0.26, respectively. These frequencies were similar to those found in other Caucasian populations. There was no significant difference in serum TC, TG, and HDL-C levels due to the influence of the genotypes. However, significant variation among the three genotypes was seen for LDL-cholesterol (p<0.001) and apo B (p<0.001) levels. Individuals homozygous for the Del allele had higher levels than individuals homozygous for the Ins allele, while individuals heterozygous for both alleles exhibited intermediate levels. When the data were analyzed in men and women separately, a similar effect was seen in both groups. Our results show that distribution of apo B insertion/deletion polymorphism in Tunisians is similar to other Caucasian population and confirm the reported association with serum LDL-cholesterol and apo B concentrations.