Increased systolic ambulatory blood pressure and microalbuminuria in treated and non‐treated hypertensive smokers

Influence of smoking and other cardiovascular risk factors on heart rate circadian rhythm in normotensive and hypertensive subjects

Circadian heart rate (HR) is influenced by hypertension and other cardiovascular risk factors particularly smoking, obesity and dyslipidemia. Until now, to evaluate the HR changes due to presence of these risk factors, a single HR office measure or a mean evaluated on day time or night time or 24h was used. However, since HR shows a circadian behavior, a single value represents only a rough approximation of this behavior. In this study, we analyzed the influence of smoking, obesity and dyslipidemia on the circadian rhythm in normotensive and hypertensive subject groups presenting only one of these risk factors. The 24h HR recordings of 170 normotensive (83 without risk factors, 20 smokers, 44 with dyslipidemia, 23 obese) and 353 hypertensive (169 without risk factors, 32 smokers, 99 with dyslipidemia, 53 obese) subjects were acquired using a Holter Blood Pressure Monitor. Results highlighted a specific circadian behavior with three characteristic periods presenting different HR means and rates of HR change in the eight subject groups. The slopes could be used both to estimate the morning HR surge associated with acute cardiovascular effects in the awakening and to evaluate the decline during the night. Moreover, we suggest to use three HR mean values (one for each identified period of the day) rather than two HR values to better describe the circadian HR behavior. Furthermore, smoking increased and dyslipidemia decreased mean HR values from 10:00 to 04:00, both in normotensive and hypertensive subjects in comparison with subjects without risk factors. In this time interval, hypertensive obese subjects showed higher values while normotensive ones presented quite similar values than subjects without risk factors. During the awakening (05:00-10:00) the slopes were similar among all groups with no significant difference among the mean HR values.

Toxicity of mercury: Molecular evidence

Minamata disease in Japan and the large-scale poisoning by methylmercury (MeHg) in Iraq caused wide public concerns about the risk emanating from mercury for human health. Nowadays, it is widely known that all forms of mercury induce toxic effects in mammals, and increasing evidence supports the concern that environmentally relevant levels of MeHg could impact normal biological functions in wildlife. The information of mechanism involved in mercurial toxicity is growing but knowledge gaps still exist between the adverse effects and mechanisms of action, especially at the molecular level. A body of data obtained from experimental studies on mechanisms of mercurial toxicity in vivo and in vitro points to that disruption of the antioxidant system may play an important role in the mercurial toxic effects. Moreover, the accumulating evidence indicates that signaling transduction, protein or/and enzyme activity, and gene regulation are involving in mediating toxic and adaptive response to mercury exposure. We conducted here a comprehensive review of mercurial toxic effects on wildlife and human, in particular synthesized key findings of molecular pathways involved in mercurial toxicity from the cells to human. We discuss the molecular evidence related mercurial toxicity to the adverse effects, with particular emphasis on the gene regulation. The further studies relying on Omic analysis connected to adverse effects and modes of action of mercury will aid in the evaluation and validation of causative relationship between health outcomes and gene expression.

Comparison of hypertension and its risk factors between the Guangxi Bai Ku Yao and Han populations

OBJECTIVE

Little is known about the prevalence of hypertension in Bai Ku Yao, an isolated subgroup of the Yao minority in China. The aim of this study was to compare the difference in the prevalence of hypertension and its risk factors between the Guangxi Bai Ku Yao and Han populations.

METHODS

A cross-sectional study of hypertension in 1170 subjects of Bai Ku Yao and 1173 participants of Han Chinese aged 15-89 was conducted by a stratified randomized cluster sampling. Information on diet and lifestyle was collected with standardized questionnaires. Blood pressure, serum lipids and several anthropometric parameters were obtained in all subjects.

RESULTS

Systolic, diastolic and pulse pressure levels and hypertension prevalence (10.85% vs 16.45%, p<0.001) were lower in Bai Ku Yao than in Han. Hypertension was positively correlated with male, age, physical activity, body mass index, waist circumference, total energy, total fat and sodium intakes, and negatively associated with education level and total dietary fibre intake in both ethnic groups (p<0.05-0.001). Hypertension was also positively associated with alcohol consumption in Han. The rates of awareness, treatment and control were lower in Bai Ku Yao than in Han (p<0.05 for all).

CONCLUSIONS

The difference in the hypertension prevalence between the two ethnic groups might result from different diet, lifestyle, physical activity level, sodium intake and genetic factors.

Sex differences in environmental and genetic factors for hypertension

BACKGROUND

Sex differences are observed in many aspects of mammalian cardiovascular function and pathology. Hypertension is more common in men than in women of the same age. Although the effects of gonadal hormones on blood pressure are considered contributing factors, the reasons for sex differences in hypertension are still not fully understood. The present study was undertaken to compare the differences in several environmental and genetic factors between men and women in the Hei Yi Zhuang, an isolated subgroup of the Zhuang minority in China.

METHODS

Information on demography, diet, and lifestyle was collected in 835 women and 834 men aged 15 to 84 years. Genotyping of angiotensin-converting enzyme, adrenergic receptor beta(3), aldehyde dehydrogenase 2, calpastatin, connexin 37, hepatic lipase, lipoprotein lipase, peroxisome proliferator-activated receptor gamma, thyrotropin-releasing hormone receptor, and von Willebrand factor also was performed in these subjects.

RESULTS

The levels of systolic and diastolic blood pressure, and the prevalence, awareness, and treatment of hypertension were lower in women than in men (P < .05). Hypertension was positively associated with age, physical activity, alcohol consumption, body mass index, waist circumference, hyperlipidemia, total energy, total fat, sodium intake, and sodium/potassium ratio, and negatively associated with education level, total dietary fiber, potassium intake, angiotensin-converting enzyme, aldehyde dehydrogenase 2, and hepatic lipase genotypes in men (P < .05). Hypertension was positively associated with age, hyperlipidemia, total energy, total fat, sodium intake, sodium/potassium ratio, calpastatin, and von Willebrand factor genotypes, and negatively associated with education level, total dietary fiber, potassium, calcium intake, lipoprotein lipase, and thyrotropin-releasing hormone receptor genotypes in women (P < .05).

CONCLUSION

Sex differences in the prevalence of hypertension in the Hei Yi Zhuang population may be mainly attributed to the differences in dietary habits, lifestyle choices, sodium and potassium intakes, physical activity level, and some genetic polymorphisms.

Effects of alcohol consumption and other lifestyle behaviors on blood pressure for the middle-aged and elderly in the Guangxi Hei Yi Zhuang and Han populations

Han is the largest group and Zhuang is the largest minority among the 56 ethnic groups in China. Geographically and linguistically, Zhuang can be classified into 43 ethnic subgroups, in which Hei Yi Zhuang is proved to be the most conservative subgroup. Little is known about the relationship between alcohol consumption and blood pressure levels in this population. Therefore, the present study was undertaken to compare the effects of alcohol consumption and other lifestyle behaviors on blood pressure levels for the middle-aged and elderly in the Guangxi Hei Yi Zhuang and Han populations. A total of 657 subjects of Hei Yi Zhuang aged 40 and older were surveyed by a stratified randomized cluster sampling. Information on demography, diet, and other lifestyle factors was collected by standard questionnaires. Anthropometric parameters and serum lipid levels were also obtained in all subjects. The results were compared with those in 520 participants of Han Chinese from the same region. The levels of systolic blood pressure and pulse pressure in Hei Yi Zhuang were higher than those in Han (P < .01-.001). Hypertension was positively correlated with sex (male), age, physical activity, alcohol consumption, serum triglyceride levels, and total energy, total fat, and salt intakes, and negatively associated with educational level in Hei Yi Zhuang (P < .05-.001), whereas positively correlated with sex (male), age, physical activity, alcohol consumption, body mass index, waist circumference, serum total cholesterol levels, and total energy, total fat, and salt intakes, and negatively associated with educational level in Han (P < .05-.001). The difference in blood pressure levels between the two ethnic groups might result from different dietary habit, lifestyle, sodium intake, educational level, physical activity, and even genetic factors.

Effects of Demographic Characteristics, Health-Related Behaviors and Lifestyle Factors on the Prevalence of Hypertension for the Middle-Aged and Elderly in the Guangxi Hei Yi Zhuang and Han Populations

BACKGROUND/AIMS

Hei Yi (meaning black worship and black dress) Zhuang is the most conservative group among the 43 ethnic subgroups of Zhuang in China due to its unique culture and customs. The prevalence of hypertension in this population has not been well defined. Therefore, the present study was undertaken to compare the effects of the demographic characteristics, health-related behaviors and lifestyle factors on the prevalence of hypertension in the middle-aged and elderly of the Guangxi Hei Yi Zhuang and Han populations.

METHODS

A total of 657 people of Hei Yi Zhuang aged 40 and over were randomly selected from 7 villages in Napo County of China. Information on the demographic characteristics, health-related behaviors and lifestyle factors was collected by questionnaire. Blood pressure, height, weight, waist circumference, serum lipid and apolipoprotein levels were measured, and body mass index (BMI) was calculated as a measure of weight relative to height. The results were compared with those of 520 Han who live in the same district.

RESULTS

The prevalence of hypertension and isolated systolic hypertension in Hei Yi Zhuang was significantly higher than in Han (32.9 vs. 24.6%, p < 0.01, and 16.7 vs. 5.2%, p < 0.001, respectively). The systolic blood pressure levels and pulse pressure in Hei Yi Zhuang were also significantly higher than in Han (129 +/- 20.1 vs. 125.8 +/- 17.4 mm Hg, p < 0.01, and 51.5 +/- 16.1 vs. 47.1 +/- 12.0 mm Hg, p < 0.01, respectively). The prevalence of hypertension was positively correlated with triglycerides, male, age, and alcohol consumption in Hei Yi Zhuang, whereas it was positively correlated with total cholesterol, male, age, alcohol consumption and BMI in Han. The rates of awareness, treatment and control in Hei Yi Zhuang and Han are 7.9 vs. 19.5%, 4.2 vs. 13.3% and 1.4 vs. 9.4% (p < 0.01 for all), respectively.

CONCLUSION

The current study reveals a significant difference in the prevalence of hypertension, blood pressure levels, and the relative factors between the Hei Yi Zhuang and Han ethnic groups, which may have been due to differences in geographical characteristics, lifestyle, sodium intake, education levels, and even genetic factors.