ABSTRACT
OBJECTIVES: To explore the effect of interaction between ACE genotype and salt intake on hypertension among Chinese Kazakhs, and to compare applications of interactions between logistic model and generalised partially linear tree-based regression (GPLTR) model. DESIGN: Population-based cross-sectional study. SETTING: Hong Dun, North Xinjiang, China. PARTICIPANTS: Non-consanguineous Chinese Kazakh participants (n=916, 342 men and 574 women) aged ≥30 years. MAIN OUTCOME MEASURES: Association between ACE genotype and hypertension, association between salt intake and hypertension, and interaction of ACE genotype and salt intake on hypertension in two models. RESULTS: Associations between salt intake and hypertension were different in ACE genotype of II and ID+DD. Under the logistic models, main and interaction effects were not observed for men, but effects were present in opposite directions for women (main effect of ACE: OR=0.20, p=0.003; interaction effect: OR=1.07, p=0.027). Under the GPLTR model, Bayesian information criterion trees included both salt intake and ACE genotype as split variables. Individuals with a salt intake ≥19.5 g/day and ID+DD genotypes had a 3.99-fold (p=0.004) higher risk of hypertension compared with the II genotype for men, whereas salt intake <20.1 g/day and ID+DD genotypes had an OR=0.55 (p=0.014) compared with the II genotype for women. CONCLUSIONS: An interaction of ACE genotype and salt intake on hypertension was observed among Chinese Kazakhs but in different ways according to sex. The GPLTR model appears to be more suitable for an exploration of interactions in complex diseases.
Subject(s)
Blood Pressure , Hypertension/genetics , Peptidyl-Dipeptidase A/genetics , Sodium Chloride, Dietary/administration & dosage , Adult , Alleles , Bayes Theorem , China , Cross-Sectional Studies , Diet , Ethnicity , Female , Gene-Environment Interaction , Genotype , Humans , Linear Models , Logistic Models , Male , Middle Aged , Multivariate Analysis , Polymorphism, Genetic , Sodium Chloride, Dietary/urineABSTRACT
Hypertension is a leading cause of death worldwide; data on hypertension among ethnic minorities in China are sparse. This study aimed to estimate hypertension prevalence, awareness, treatment, and control in a Kazakh population, and to assess the association between salt intake and the above measures. A cross-sectional survey was conducted among Kazakh adults (≥30 years old) in the town of Hongdun, Altay, Xinjiang. Survey procedures included a questionnaire, physical measurement, and laboratory tests. Of 1805 eligible individuals, 1668 (92.4%) were included in the analysis. After adjustment for gender, age, and occupation, prevalence of hypertension was 45.5%. The proportions with awareness, treatment, control, or medication-control were 61.0%, 28.8%, 2.9% and 10.1%, respectively. Higher prevalence was seen among nomads and farmers (50.7% and 44.6%, respectively). However, the proportions with treatment or control were lower than seen among urban citizens. Hypertension prevalence was higher in those with higher salt intake (p = 0.0008). In contrast, the proportions with awareness (p = 0.0389), treatment (p = 0.0010), control (p = 0.0503), and medication-control (p = 0.2012) reduced as salt intake increased. In conclusion, hypertension prevalence is high in this population, but the proportions with awareness, treatment, or control are sub-optimal. Public health interventions that improve hypertension prevention and control, particularly among nomads, is needed.
Subject(s)
Health Knowledge, Attitudes, Practice , Hypertension/ethnology , Hypertension/prevention & control , Sodium Chloride, Dietary/adverse effects , Adult , Aged , Asian People/ethnology , China/ethnology , Cross-Sectional Studies , Female , Humans , Kazakhstan/ethnology , Male , Middle Aged , PrevalenceABSTRACT
BACKGROUND: A relationship of blood uric acid (UA) with hypertension and cardiovascular risk is under debate thus salt intake is hypothesized to contribute to such associations. METHODS: In this cross-sectional study, stratified cluster random sampling elicited a sample of 1805 Kazakhs with 92.4% compliance. Hypertension and moderate-or-high total cardiovascular risk (mTCR) were defined according to guidelines. Sodium intake was assessed by urinary sodium excretion. Prevalence ratios (PRs) were used to express associations of UA with hypertension and mTCR. RESULTS: In the highest tertile of sodium intake in women, the adjusted PRs (95% confidence intervals) of low to high quartiles compared with the lowest quartile of UA, were 1.22(0.78-1.91), 1.18(0.75-1.85), and 1.65(1.09-2.51) for hypertension and 1.19(0.74-1.90), 1.39(0.91-2.11), and 1.65(1.10-2.47) for mTCR (P for trend <0.05). However, these findings were not shown for other sodium intake levels. There were similar results in men. PRs markedly increased with a concomitant increase in UA and sodium intake and there was a significant interaction (P = 0.010) for mTCR with PRs of 1.69(1.10-2.60) for men and 3.70(2.09-6.52) for women in those with the highest compared with the lowest quartile of UA and tertile of sodium intake. Similar findings were shown for hypertension. CONCLUSIONS: This study implied that a high salt intake may enhance the associations of UA with hypertension and cardiovascular risk.
