Body mass index, nocturnal fall in blood pressure and organ damage in untreated essential hypertensive patients

The influence of body composition and fat distribution on circadian blood pressure rhythm and nocturnal mean arterial pressure dipping in patients with obesity

Loss of physiological nocturnal blood pressure (BP) decline is an independent predictor of cardiovascular risk and mortality. The aim of the study was to investigate the influence of body composition and fat distribution on 24-hour BP pattern and nocturnal dipping of mean arterial pressure (MAP) in patients with obesity. The study comprised 436 patients, 18 to 65 years old (306 women), with BMI ≥30 kg/m2. Body composition was assessed with dual-energy X-ray absorptiometry (DXA) and blood pressure was assessed by 24-hour BP monitoring. The prevalence of hypertension was 64.5% in patients with BMI <40 kg/m2 and increased to 78.7% in individuals with BMI ≥50 kg/m2 (p = 0.034). The whole-body DXA scans showed that the hypertensive patients were characterized by a greater lean body mass (LBM) and a higher abdominal-fat-to-total-fat-mass ratio (AbdF/FM), while the normotensive participants had greater fat mass, higher body fat percentage and more peripheral fat. Loss of physiological nocturnal MAP decline was diagnosed in 50.2% of the patients. The percentage of non-dippers increased significantly: from 38.2% in patients with BMI <40 kg/m2 to 50.3% in those with BMI 40.0-44.9 kg/m2, 59.0% in patients with BMI 45.0-49.9 kg/m2, 71.4% in those with BMI 50.0-54.9 kg/m2 and 83.3% in patients with BMI ≥55 kg/m2 (p = 0.032, p = 0.003, p<0.001, and p = 0.002 vs. BMI <40 kg/m2, respectively). The multivariable regression analysis showed that patients at the highest quartiles of body weight, BMI, LBM and AbdF/FM had significantly reduced nocturnal MAP dipping compared with patients at the lowest quartiles, respectively.

The Tri-ponderal Mass Index is associated with adiposity in adolescent type 2 diabetes mellitus: a cross-sectional analysis

Pediatric type 2 diabetes mellitus (T2DM) patients are often overweight or obese, yet there are no validated clinical measures of adiposity to stratify cardiometabolic risk in this population. The tri-ponderal mass index (TMI, kg/m³) has recently been reported as a measure of adiposity in children, but there has been no validation of the association of TMI with adiposity in pediatric T2DM. We hypothesized that in children with T2DM, the TMI can serve as a more accurate measure of adiposity when compared to BMI z-score, and that it is associated with components of the metabolic syndrome. This is a cross-sectional secondary data analysis from the Improving Renal Complications in Adolescents with Type 2 Diabetes Through REsearch (iCARE) study (n = 116, age 10.20–17.90 years). Spearman’s correlations and multivariable regression were used in the analyses. When compared to DXA, TMI demonstrated significant correlation with total adiposity versus BMI z-score (TMI r = 0.74, p-value < 0.0001; BMI z-score r = − 0.08, p-value 0.403). In regression analyses, TMI was associated with WHtR (B = 35.54, 95% CI 28.81, 42.27, p-value < 0.0001), MAP dipping (B = 1.73, 95% CI 0.12, 3.33, p-value = 0.035), and HDL (B = − 5.83, 95% CI − 10.13, − 1.54, p-value = 0.008). In conclusion, TMI is associated with adiposity and components of the metabolic syndrome in pediatric T2DM patients.

Diurnal Regulation of Renal Electrolyte Excretion: The Role of Paracrine Factors

Many physiological processes, including most kidney-related functions, follow specific rhythms tied to a 24-h cycle. This is largely because circadian genes operate in virtually every cell type in the body. In addition, many noncanonical genes have intrinsic circadian rhythms, especially within the liver and kidney. This new level of complexity applies to the control of renal electrolyte excretion. Furthermore, there is growing evidence that paracrine and autocrine factors, especially the endothelin system, are regulated by clock genes. We have known for decades that excretion of electrolytes is dependent on time of day, which could play an important role in fluid volume balance and blood pressure control. Here, we review what is known about the interplay between paracrine and circadian control of electrolyte excretion. The hope is that recognition of paracrine and circadian factors can be considered more deeply in the future when integrating with well-established neuroendocrine control of excretion.

Novel Approaches to Investigate One-Carbon Metabolism and Related B-Vitamins in Blood Pressure

Hypertension, a major risk factor for heart disease and stroke, is the world's leading cause of preventable, premature death. A common polymorphism (677C→T) in the gene encoding the folate metabolizing enzyme methylenetetrahydrofolate reductase (MTHFR) is associated with increased blood pressure, and there is accumulating evidence demonstrating that this phenotype can be modulated, specifically in individuals with the MTHFR 677TT genotype, by the B-vitamin riboflavin, an essential co-factor for MTHFR. The underlying mechanism that links this polymorphism, and the related gene-nutrient interaction, with hypertension is currently unknown. Previous research has shown that 5-methyltetrahydrofolate, the product of the reaction catalysed by MTHFR, appears to be a positive allosteric modulator of endothelial nitric oxide synthase (eNOS) and may thus increase the production of nitric oxide, a potent vasodilator. Blood pressure follows a circadian pattern, peaking shortly after wakening and falling during the night, a phenomenon known as 'dipping'. Any deviation from this pattern, which can only be identified using ambulatory blood pressure monitoring (ABPM), has been associated with increased cardiovascular disease (CVD) risk. This review will consider the evidence linking this polymorphism and novel gene-nutrient interaction with hypertension and the potential mechanisms that might be involved. The role of ABPM in B-vitamin research and in nutrition research generally will also be reviewed.

Associations between body mass index, ambulatory blood pressure findings, and changes in cardiac structure: relevance of pulse and nighttime pressures

Ambulatory blood pressure monitoring (ABPM) is central in the management of hypertension. Factors related to BP, such as body mass index (BMI), may differently affect particular aspects of 24-hour ABPM profiles. However, the relevance of BMI, the most used index of adiposity, has been underappreciated in the determination of specific aspects of 24-hour ABPM profiles in hypertension. The authors evaluated the association between BMI and aspects of ABPM together with their associations with cardiac remodeling in 1841 patients. A positive association of BMI with 24-hour, daytime, and nighttime pulse pressure in untreated normal weight and overweight/obese hypertensive patients and a positive association of BMI with nocturnal BP parameters in treated overweight/obese hypertensive patients was observed. The clinical relevance of these findings was supported by the positive significant correlations of BMI-related BPs with left ventricular mass and atrial diameter.

Circadian blood pressure pattern in sarcoidosis patients

OBJECTIVES

Autonomic dysfunction (AD) is frequent in sarcoidosis and considered a result of small fiber neuropathy. A non-dipper blood pressure (BP) pattern, which is also linked to AD, is associated with increased risk of cardiovascular and renal diseases. The aim of the present study was to evaluate the non-dipping BP pattern in normotensive patients with pulmonary sarcoidosis (PS).

METHODS

Sixty-three normotensive patients with PS (group 1) and 49 healthy subjects (group 2) were prospectively enrolled. Ambulatory BP monitoring was performed in all participants over a 24-h period.

RESULTS

The non-dipping BP pattern was significantly more frequent in patients with PS compared with the control group (80% vs 53%, respectively, p = 0.002). More advanced PS (grade 2) was an independent predictor of non-dipper BP pattern (odds ratio = 10.4, 95% confidence interval 1.1-95.4, p = 0.03). Masked hypertension and body mass index were also found to be other predictors of non-dipping BP pattern.

CONCLUSIONS

The present study showed that non-dipping BP pattern is frequently observed in normotensive patients with PS. The probable mechanism underlying the non-dipping BP in PS is autonomic nervous system dysfunction. PS represents an independent risk factor for non-dipping BP and these patients have increased cardiovascular risk.

The relationship between nocturnal blood pressure and hemorrhagic stroke in Chinese hypertensive patients

To study the relationship between nocturnal blood pressure (BP) variation and spontaneous intracerebral hemorrhage (ICH) among Chinese hypertensive patients and its clinical significance, the authors retrospectively screened 371 patients with primary hypertension (189 patients with ICH, 182 patients without ICH) in Shanghai and analyzed their demographics, clinical information, nocturnal blood pressure variability and medication. Compared with the control group, the levels of blood glucose, triglycerides, and creatinine were significantly increased in the ICH group, along with a marked reduction in nocturnal BP drop (P<.05). Multivariate logistic regression indicated that blood glucose, creatinine, and nocturnal mean arterial pressure were risk factors for ICH, and the magnitude of nocturnal BP drop was negatively related to the risk for ICH. There was no significant difference in the prevalence of reverse dippers between the large hematoma volume group and the small hematoma volume group (χ(2) =2.529, P=.112), nor among the patients taking angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, or calcium channel blockers (χ(2) =1.981, P=.371). Reverse dipping is associated with the risk for ICH, suggesting that appropriate antihypertensive drug and chronotherapy might be effective to normalize the rhythm of abnormal circadian variation in hypertensive patients.

Neighborhood problems and nocturnal blood pressure dipping

OBJECTIVE

Living in adverse neighborhood conditions has been linked with greater prevalence of cardiovascular disease (CVD). We aimed to learn whether perceived neighborhood problems are related to attenuated nocturnal blood pressure (BP) dipping, a risk factor for CVD morbidity.

METHOD

A sample of 133 adults (71 male, 62 female; 80 White, 53 Black) underwent 24-hr ambulatory blood pressure monitoring. The neighborhood problem scale (NPS) was used to assess neighborhood environmental stressors.

RESULTS

Nocturnal dipping in systolic (SBP), diastolic (DBP) and mean arterial (MAP) blood pressure was reduced in individuals with higher NPS scores (p < .05). Hierarchical regression analyses revealed that neighborhood problems explained 4%-6% of the variance in SBP, DBP, and MAP dipping (p < .05) even after adjusting for several theoretical confounders such as social status, age, gender, race, body mass index (BMI), smoking, exercise, depression and discrimination.

CONCLUSION

Neighborhood problems may contribute to attenuated BP dipping beyond the effect of known risk factors.

Echocardiographic indices of left ventricular hypertrophy and diastolic function in hypertensive patients with preserved LVEF classified as dippers and non-dippers

INTRODUCTION

Long-lasting arterial hypertension causes left ventricular hypertrophy (LVH) and impairs left ventricular diastolic function. Our aim was to compare echocardiographic parameters between hypertensive patients defined as dippers and non-dippers during ambulatory blood pressure (BP) monitoring.

MATERIAL AND METHODS

We analysed 61 consecutive subjects with treated hypertension undergoing 24-h BP monitoring and transthoracic echocardiographic examination and included in the study patients with preserved left ventricular ejection fraction (EF ≥ 50%). Echocardiographic and arterial pressure parameters were compared between the group classified as dippers (n = 26, 57 ±13 years, 16 males) and non-dippers (n = 35, 60 ±12 years, 24 males) according to present or absent decrease of BP during the night > 10%. Echocardiographic data were compared between both groups and control subjects without hypertension.

RESULTS

Dippers had lower average systolic, diastolic and mean arterial pressure during the night hours but did not differ according to the mean pressure calculated from a 24-hour period. All echocardiographic parameters were similar in dippers and non-dippers. All patients with arterial hypertension presented with larger dimension of both ventricles and left atrium, thicker left ventricular walls, higher LV mass and mass index and preserved EF and E/A ratio as compared with normotensive controls. Normal geometry, concentric remodelling and eccentric hypertrophy were similarly distributed in both groups. Concentric hypertrophy was more prevalent in non-dippers as compared to the dippers (71.4% vs. 38.5%, p < 0.043).

CONCLUSIONS

The concentric type of LVH is the prevalent pattern in non-dippers. Non-dipping blood pressure pattern may be responsible for the development of left ventricular concentric hypertrophy secondary to hypertension.

Non-dipping nocturnal blood pressure in psoriasis vulgaris

BACKGROUND

Psoriasis vulgaris is one of the most prevalent chronic, inflammatory skin disorders. Patients with psoriasis carry an excess risk of hypertension and adverse cardiovascular (CV) events. Blood pressure (BP) has a circadian rhythm characterised with lower values at night. A blunted nocturnal BP decline defined as non-dipping accelerates the development of hypertension and CV diseases. The aim of this study is to evaluate circadian variation of blood pressure in normotensive middle-aged patients with psoriasis vulgaris.

METHODS

Seventy adult patients with psoriasis vulgaris (group 1) and 70 age and sex-matched healthy individuals (group 2) were included in the study. Ambulatory BP monitoring was performed in all participants over a 24-h period. Non-dippers are defined as those who show a reduction in BP of less than 10 % between the average day and night systolic BP.

RESULTS

Although mean 24-h BPs were similar in both groups, night-time BPs were significantly higher in psoriatic patients (115.1 ± 7.7 vs. 109.9 ± 6.0 mmHg and 72.1 ± 7.0 vs. 67.6 ± 5.5 mmHg, respectively; p < 0.05). The non-dipping pattern of BP changes was significantly more common in patients with psoriasis vulgaris compared with the control group (65.9 vs. 34.1 %, p < 0.01). Psoriasis severity and BMI are independent predictors of impaired nocturnal BP regulation.

CONCLUSIONS

Patients with psoriasis vulgaris had increased nocturnal BP and heart rate. This is the first study to demonstrate a blunted nocturnal BP decrease in normotensive patients with psoriasis.

The effect of zolpidem on sleep quality, stress status, and nondipping hypertension

OBJECTIVE

Poor sleep quality and stress status have previously been shown to be closely associated with higher activation of the sympathetic nervous system and to be independent predictors of nondipping hypertension. This study aimed to evaluate the effects of the non-hypotensive sedative zolpidem on sleep quality, stress status, and nondipping hypertension.

METHODS

A total of 103 nondippers were defined as poor or good sleepers by the Pittsburgh Sleep Quality Index. They were randomized to receive zolpidem or placebo treatment for 30 days. Stress status was assessed by the Perceived Stress Scale, and levels of epinephrine and norepinephrine were examined to investigate the underlying mechanisms.

RESULTS

Poor sleepers treated with zolpidem for 30 days showed significant improvements in sleep quality and stress levels (P<0.01). More nondippers were converted to dippers in the group of poor sleepers treated with zolpidem (11 of 22 patients, 50.0%) than in the placebo (2 of 23, 8.7%) (P<0.01). Epinephrine and norepinephrine levels were significantly reduced in poor sleepers treated with zolpidem (P<0.05).

CONCLUSION

The results of this study suggest that zolpidem can improve sleep quality and stress status, and can convert nondippers with poor sleep quality into dippers. It may be an option for treating nondipping hypertensive patients with poor sleep quality.

Behavioural and psychosocial correlates of nondipping blood pressure pattern among middle-aged men and women at work

The underlying pathogenetic mechanisms of nondipping blood pressure (BP) pattern are not completely understood. Especially the role of psychosocial correlates remains unclear. The aim was to assess the association between nondipping BP pattern, behavioural and psychosocial factors in a sample of working men and women. The study sample included 167 working men and women aged 40-64 years from the BELSTRESS cohort. Socio-demographic, behavioural and psychosocial factors were assessed by self-administered questionnaires. Participants were medically examined and underwent an ambulatory BP monitoring during 24 h. Nondipping was defined when the average nocturnal decline in BP was <10%. The prevalence of nondipping for both systolic and diastolic BP was 7.8%. Nondipping was not significantly related to smoking, alcohol consumption and leisure time physical activity. A crude significant association was observed between nondipping and sleep problems. After adjusting for gender, education and body mass index, the risk for nondipping was associated with job strain, living alone, being unsatisfied about the contact with one's children, depressive symptoms and vital exhaustion. Nondipping BP pattern was consistently related to psychosocial factors in this study: positive associations were observed with measures of job strain, poor private life support (living alone and being unsatisfied about the contact with one's children) and mental health problems (depressive symptoms and vital exhaustion).