Ethnic differences in the effects of the DASH diet on nocturnal blood pressure dipping in individuals with high blood pressure

Mediterranean lifestyle index and 24-h systolic blood pressure and heart rate in community-dwelling older adults

Specific foods, nutrients, dietary patterns, and physical activity are associated with lower blood pressure (BP) and heart rate (HR), but little is known about the joint effect of lifestyle factors captured in a multidimensional score. We assessed the association of a validated Mediterranean-lifestyle (MEDLIFE) index with 24-h-ambulatory BP and HR in everyday life among community-living older adults. Data were taken from 2,184 individuals (51% females, mean age: 71.4 years) from the Seniors-ENRICA-2 cohort. The MEDLIFE index consisted of 29 items arranged in three blocks: 1) Food consumption; 2) Dietary habits; and 3) Physical activity, rest, and conviviality. A higher MEDLIFE score (0-29 points) represented a better Mediterranean lifestyle adherence. 24-h-ambulatory BP and HR were obtained with validated oscillometric devices. Analyses were performed with linear regression adjusted for the main confounders. The MEDLIFE-highest quintile (vs Q1) was associated with lower nighttime systolic BP (SBP) (-3.17 mmHg [95% CI: -5.25, -1.08]; p-trend = 0.011), greater nocturnal-SBP fall (1.67% [0.51, 2.83]; p-trend = 0.052), and lower HR (-2.04 bpm [daytime], -2.33 bpm [nighttime], and -1.93 bpm [24-h]; all p-trend < 0.001). Results were similar for each of the three blocks of MEDLIFE and by hypertension status (yes/no). Among older adults, higher adherence to MEDLIFE was associated with lower nighttime SBP, greater nocturnal-SBP fall, and lower HR in their everyday life. These results suggest a synergistic BP-related protection from the components of the Mediterranean lifestyle. Future studies should determine whether these results replicate in older adults from other Mediterranean and non-Mediterranean countries.

Rationale and study protocol for a randomized controlled feeding study to determine the structural- and functional-level effects of diet-specific interventions on the gut microbiota of non-Hispanic black and white adults

BACKGROUND

Colorectal cancer (CRC), the third leading cause of cancer-related deaths in the US, has been associated with an overrepresentation or paucity of several microbial taxa in the gut microbiota, but causality has not been established. Black men and women have among the highest CRC incidence and mortality rates of any racial/ethnic group. This study will examine the impact of the Dietary Approaches to Stop Hypertension (DASH) diet on gut microbiota and fecal metabolites associated with CRC risk.

METHODS

A generally healthy sample of non-Hispanic Black and white adults (n = 112) is being recruited to participate in a parallel-arm randomized controlled feeding study. Participants are randomized to receive the DASH diet or a standard American diet for a 28-day period. Fecal samples are collected weekly throughout the study to analyze changes in the gut microbiota using 16 s rRNA and selected metagenomics. Differences in bacterial alpha and beta diversity and taxa that have been associated with CRC (Bacteroides, Fusobacterium, Clostridium, Lactobacillus, Bifidobacterium, Ruminococcus, Porphyromonas, Succinivibrio) are being evaluated. Covariate measures include body mass index, comorbidities, medication history, physical activity, stress, and demographic characteristics.

CONCLUSION

Our findings will provide preliminary evidence for the DASH diet as an approach for cultivating a healthier gut microbiota across non-Hispanic Black and non-Hispanic White adults. These results can impact clinical, translational, and population-level approaches for modification of the gut microbiota to reduce risk of chronic diseases including CRC.

TRIAL REGISTRATION

This study was registered on ClinicalTrials.gov, identifier NCT04538482, on September 4, 2020 (https://clinicaltrials.gov/ct2/show/NCT04538482).

Dietary Approaches to Stop Hypertension (DASH)-Style Dietary Pattern and 24-Hour Ambulatory Blood Pressure in Elderly Chinese with or without Hypertension

BACKGROUND

It is unknown whether the Dietary Approaches to Stop Hypertension (DASH) dietary pattern is associated with other blood pressure (BP) variables, beyond mean systolic blood pressure (SBP) and diastolic blood pressure (DBP).

OBJECTIVES

The study aimed to study the associations between the DASH dietary pattern and daytime and nighttime mean BPs and BP variance independent of the mean (VIM).

METHODS

A sample of 324 Chinese adults aged ≥ 60 y who were not on BP-lowering medications were included in the analysis. The DASH score was calculated using data collected by a validated FFQ. The 24-h ambulatory BP was measured and the mean and VIM SBP and DBP were calculated for both the daytime (06:00-21:59) and nighttime periods (22:00-05:59). Multivariable linear models were constructed to assess associations between the DASH dietary pattern and daytime and nighttime BP outcomes, adjusting for sociodemographic factors, lifestyle, BMI, and hypertension (clinic SBP ≥ 140 mm Hg or DBP ≥ 90 mm Hg), and sleep parameters (only for nighttime BP outcomes). An interaction term between DASH score and hypertension status was added to explore the potential differential association in normotensive and hypertensive individuals.

RESULTS

Every 1-unit increase in the DASH score was associated with a 0.18-unit (95% CI: -0.34, -0.01 unit) and a 0.22-unit (95% CI: -0.36, -0.09 unit) decrease in nighttime VIM SBP and nighttime VIM DBP, respectively. DASH score was not associated with any daytime BP outcomes, nighttime mean SBP, or nighttime mean DBP. A significant interaction (DASH score × hypertension status) was detected for VIM SBP (P-interaction = 0.04), indicating a differential association between DASH score and nighttime VIM SBP by hypertension status.

CONCLUSIONS

Independently of sleep parameters and other factors, the DASH dietary pattern is associated with lower nighttime BP variability in elderly adults.

A Systematic Review of Literature on the Representation of Racial and Ethnic Minority Groups in Clinical Nutrition Interventions

The racial and ethnic disparities in diet-related chronic diseases are major concerns. This systematic review examines the extent to which diet-induced changes in health outcomes, such as cardiometabolic, inflammation, cancer, bone health, and kidney function outcomes, etc., have been reported and discussed by race or ethnicity in randomized trials with 2 or more diet arms that recruited both minority and non-Hispanic White groups. Databases (i.e., PubMed, Cochrane Library, and Web of Science) were searched up to August 2021. Thirty-four studies that discussed effects of defined dietary interventions on health outcomes by racial or ethnic minority group compared with non-Hispanic Whites were included in the systematic review (PROSPERO registration number: CRD42021229256). Acute trials and those with 1 diet arm that accounted for race or ethnicity in their analyses and studies that focused on a single racial or ethnic group were discussed separately. Most studies were conducted in Black compared with White adults testing effects of energy restriction, macronutrient modification, sodium reduction, or variations of the Dietary Approaches to Stop Hypertension (DASH) diet on cardiometabolic outcomes. There was limited focus on other minority groups. Evidence suggests greater blood pressure reduction for Black adults compared with Whites particularly with DASH (or similar) diets. Overall, there was limited consideration for group-specific eating patterns and diet acceptability. Overall risk of bias was low. With emerging precision nutrition initiatives that aim to optimize metabolic responses in population subgroups through tailored approaches, it is imperative to ensure adequate representation of racial and ethnic subgroups for addressing health disparities. Factors that help explain variability in responses such as socioecological context should be included and adequately powered. Given the racial and ethnic disparities in chronic diseases, studying the adoption, maintenance, and effectiveness of dietary interventions on health outcomes among different groups is critical for developing approaches that can mitigate diet-related health disparities.

A Whole-Diet Approach Affects Not Only Fasting but Also Postprandial Cardiometabolic Risk Markers in Overweight and Obese Adults: A Randomized Controlled Trial

BACKGROUND

Current dietary recommendations for cardiovascular disease (CVD) prevention focus more on dietary patterns than on single nutrients. However, randomized controlled trials using whole-diet approaches to study effects on both fasting and postprandial CVD risk markers are limited.

OBJECTIVE

This randomized parallel trial compared the effects of a healthy diet (HD) with those of a typical Western diet (WD) on fasting and postprandial CVD risk markers in overweight and obese adults.

METHODS

After a 2-wk run-in period, 40 men and women (50-70 y; BMI: 25-35 kg/m2) consumed the HD (high in fruit and vegetables, pulses, fibers, nuts, fatty fish, polyunsaturated fatty acids; low in salt and high-glycemic carbohydrates; n = 19) or the WD (less fruit, vegetables, and fibers; no nuts and fatty fish; and more saturated fatty acids and simple carbohydrates; n = 21) for 6 wk. Fasting and postprandial cardiometabolic risk markers were assessed as secondary outcome parameters during a 5-h mixed-meal challenge, and a per protocol analysis was performed using 1-factor ANCOVA or linear mixed models.

RESULTS

Differences in diet-induced changes are expressed relative to the HD group. Changes in fasting plasma total cholesterol (-0.57 ± 0.12 mmol/L, P < 0.001), LDL cholesterol (-0.41 ± 0.12 mmol/L, P < 0.01), apolipoprotein B100 (-0.09 ± 0.03 g/L, P < 0.01), and apolipoprotein A1 (-0.06 ± 0.03 g/L, P = 0.05) were significantly different between the diet groups. Changes in postprandial plasma triacylglycerol (diet × time, P < 0.001) and apolipoprotein B48 (P < 0.01) differed significantly between the groups with clear improvements on the HD, although fasting triacylglycerols (-0.24 ± 0.13 mmol/L, P = 0.06) and apolipoprotein B48 (1.04 ± 0.67 mg/L, P = 0.40) did not. Significant differences between the diets were also detected in fasting systolic (-6.9 ± 3.1 mmHg, P < 0.05) and 24-h systolic (-5.0 ± 1.7 mmHg, P < 0.01) and diastolic (-3.3 ± 1.1 mmHg, P < 0.01) blood pressure.

CONCLUSION

A whole-diet approach targeted multiple fasting and postprandial CVD risk markers in overweight and obese adults. In fact, the postprandial measurements provided important additional information to estimate CVD risk. This trial is registered at clinicaltrials.gov as NCT02519127.

Health Behaviors, Nocturnal Hypertension, and Non-dipping Blood Pressure: The Coronary Artery Risk Development in Young Adults and Jackson Heart Study

BACKGROUND

Several health behaviors have been associated with hypertension based on clinic blood pressure (BP). Data on the association of health behaviors with nocturnal hypertension and non-dipping systolic BP (SBP) are limited.

METHODS

We analyzed data for participants with ambulatory BP monitoring at the Year 30 Coronary Artery Risk Development in Young Adults (CARDIA) study exam in 2015-2016 (n = 781) and the baseline Jackson Heart Study (JHS) exam in 2000-2004 (n = 1,046). Health behaviors (i.e., body mass index, physical activity, smoking, and alcohol intake) were categorized as good, fair, and poor and assigned scores of 2, 1, and 0, respectively. A composite health behavior score was calculated as their sum and categorized as very good (score range = 6-8), good (5), fair (4), and poor (0-3). Nocturnal hypertension was defined as mean asleep SBP ≥ 120 mm Hg or mean asleep diastolic BP ≥ 70 mm Hg and non-dipping SBP as < 10% awake-to-asleep decline in SBP.

RESULTS

Among CARDIA study and JHS participants, 41.1% and 56.9% had nocturnal hypertension, respectively, and 32.4% and 72.8% had non-dipping SBP, respectively. The multivariable-adjusted prevalence ratios (95% confidence interval) for nocturnal hypertension associated with good, fair, and poor vs. very good health behavior scores were 1.03 (0.82-1.29), 0.98 (0.79-1.22), and 0.96 (0.77-1.20), respectively in CARDIA study and 0.98 (0.87-1.10), 0.96 (0.86-1.09), and 0.86 (0.74-1.00), respectively in JHS. The health behavior score was not associated non-dipping SBP in CARDIA study or JHS after multivariable adjustment.

CONCLUSIONS

A health behavior score was not associated with nocturnal hypertension or non-dipping SBP.

Associations of the dietary approaches to stop hypertension (DASH) diet with pregnancy complications in Project Viva

BACKGROUND/OBJECTIVES

The Dietary Approaches to Stop Hypertension (DASH) diet has been shown to improve cardiometabolic outcomes in non-pregnant populations. Little is known regarding the impact of this diet on health during pregnancy. The objective of this research is to examine associations of adherence to the DASH diet with hypertensive disorders of pregnancy (HDP) and other pregnancy outcomes.

SUBJECTS/METHODS

We conducted analyses with data that came from 1760 women in Project Viva, a Boston-area longitudinal cohort recruited in early pregnancy 1999-2002. We derived a DASH score using data from a food frequency questionnaire (FFQ) administered at median 11.1 weeks gestation. Next, we used multivariable linear regression models that accounted for the woman's age at enrollment, pre-pregnancy body mass index (BMI), education, smoking habits, race/ethnicity, gestational weight gain (GWG) up until the time of the FFQ, and total energy intake to examine associations of the DASH score with HDP, gestational diabetes, preterm delivery (<37 weeks), birth size, and GWG from FFQ to delivery. Models for HDP and GDM were additionally mutually adjusted for each other. Because pre-pregnancy weight status may modify these relationships, we tested for interactions between pre-pregnancy BMI and the DASH score.

RESULTS

Mean ± SD age of the women was 32.2 ± 4.9 years; 71.9% were white. Overall, the DASH diet score (mean: 24.0, SD: 5.0) was not associated with any of the pregnancy outcomes or complications. However, we found a positive association between the DASH diet and subsequent GWG among women who were obese before pregnancy (0.19 [95% CI: 0.05, 0.34], P ≤ 0.05 kg higher GWG per 1 unit DASH score).

CONCLUSIONS

Adherence to DASH diet during early pregnancy does not appear to be protective against HDP or other adverse pregnancy outcomes.

Ambulatory blood pressure in the dash diet trial: Effects of race and albuminuria

We evaluated whether low-grade albuminuria or black race modulates ambulatory blood pressure (BP) or nocturnal BP response to the DASH diet. Among 202 adults enrolled in the DASH multicenter trial who were fed the DASH or control diet for 8 weeks, reductions in 24-hour daytime and nighttime SBP and DBP were significantly larger for DASH compared to control. Median changes in nocturnal BP dipping were not significant. Compared to urine albumin excretion of <7 mg/d, ≥7 mg/d was associated with larger significant median reductions in 24-hour SBP (-7.3 vs -3.1 mm Hg), all measures of DBP (24-hour: -5.9 vs -1.8 mm Hg; daytime: -9.9 vs -4.0 mm Hg; nighttime -9.0 vs -2.0 mm Hg), and with increased nocturnal SBP dipping (2.3% vs -0.5%). Black race was associated with larger median reduction in 24-hour SBP only (-5.5 vs -2.4 mm Hg). This analysis suggests greater effect of DASH on ambulatory BP in the presence of low-grade albuminuria.

Influence of Kidney Function on Blood Pressure Response to Lifestyle Modifications: Secondary Analysis From the Exercise and Nutritional Interventions for Cardiovascular Health (ENCORE) Trial

The kidney is an important regulator of blood pressure (BP). To determine whether BP response to lifestyle modification varies across normal ranges of kidney function, the authors examined the moderating role of estimated glomerular filtration rate (eGFR) on clinic and ambulatory systolic BP (SBP) response in overweight and obese adults with unmedicated high BP. Among 144 participants of the Exercise and Nutritional Interventions for Cardiovascular Health (ENCORE) trial, mean age was 52.0±9.6 years and median eGFR was 89.1 (53-146) mL/min/1.73m2 . After multivariable regression, the interaction between eGFR and weight loss was significant for clinic (P=.023) and ambulatory SBP (P=.041). Similarly, the interaction between eGFR and improved fitness was significant for clinic (P=.041) and ambulatory SBP (P=.044). The relationship between reduced dietary sodium and SBP was not moderated by eGFR. SBP findings were inconsistent for adherence to the Dietary Approaches to Stop Hypertension (DASH) diet. These findings suggest that the effects of lifestyle modifications on SBP may be influenced by eGFR, even when kidney function is preserved.

Short-term effects of the DASH diet in adults with moderate chronic kidney disease: a pilot feeding study

Background

Although the Dietary Approaches to Stop Hypertension (DASH) diet lowers blood pressure (BP) for adults with normal kidney function, evidence is lacking regarding its safety and efficacy in chronic kidney disease (CKD). We aimed to test the effects of the DASH diet on serum electrolytes and BP in adults with moderate CKD.

Methods

In a prospective before–after feeding study, 11 adults with an estimated glomerular filtration rate of 30–59 mL/min/1.73 m² and medication-treated hypertension were provided a reduced-sodium, run-in diet for 1 week followed by a reduced-sodium, DASH diet for 2 weeks. Changes in serum electrolytes and BP were compared pre–post DASH.

Results

Eleven participants underwent feeding; 1 completed 1 week and 10 completed 2 weeks of DASH. Compared with baseline, DASH modestly increased serum potassium at 1 week (mean ± standard deviation, +0.28 ± 0.4 mg/dL; P = 0.043) but had no significant effect on potassium at 2 weeks (+0.15 ± 0.28 mg/dL; P = 0.13). Serum bicarbonate was reduced (−2.5 ± 3.0 mg/dL; P = 0.03) at 2 weeks. Neither incident hyperkalemia nor new onset metabolic acidosis was observed. Clinic BP and mean 24-h ambulatory BP was unchanged. DASH significantly reduced mean nighttime BP (−5.3 ± 5.8 mmHg; P = 0.018), and enhanced percent declines in both nocturnal systolic BP (−2.1% to −5.1%; P = 0.004) and diastolic BP (−3.7% to −10.0%; P = 0.008).

Conclusions

These pilot data suggest that a reduced-sodium DASH dietary pattern does not cause acute metabolic events in adults with moderate CKD and may improve nocturnal BP. Definitive studies are needed to determine long-term effects of DASH in CKD.

Lifestyle modification for resistant hypertension: The TRIUMPH randomized clinical trial

BACKGROUND

Resistant hypertension (RH) is a growing health burden in this country affecting as many as 1 in 5 adults being treated for hypertension. Resistant hypertension is associated with increased risk of adverse cardiovascular disease (CVD) events and all-cause mortality. Strategies to reduce blood pressure (BP) in this high-risk population are a national priority.

METHODS

TRIUMPH is a single-site, prospective, randomized clinical trial to evaluate the efficacy of a center-based lifestyle intervention consisting of exercise training, reduced sodium and calorie Dietary Approaches to Stop Hypertension eating plan, and weight management compared to standardized education and physician advice in treating patients with RH. Patients (n = 150) will be randomized in a 2:1 ratio to receive either a 4-month supervised lifestyle intervention delivered in the setting of a cardiac rehabilitation center or to a standardized behavioral counseling session to simulate real-world medical practice. The primary end point is clinic BP; secondary end points include ambulatory BP and an array of CVD biomarkers including left ventricular hypertrophy, arterial stiffness, baroreceptor reflex sensitivity, insulin resistance, lipids, sympathetic nervous system activity, and inflammatory markers. Lifestyle habits, BP, and CVD risk factors also will be measured at 1-year follow-up.

CONCLUSIONS

The TRIUMPH randomized clinical trial (ClinicalTrials.gov NCT02342808) is designed to test the efficacy of an intensive, center-based lifestyle intervention compared to a standardized education and physician advice counseling session on BP and CVD biomarkers in patients with RH after 4 months of treatment and will determine whether lifestyle changes can be maintained for a year.

The primary care physician/nephrologist partnership in treating chronic kidney disease

Chronic kidney disease (CKD) continues to be an ever-increasing health problem in the United States and elsewhere. Diabetes mellitus and hypertension remain the primary causes, and much of this is related to increased rates of obesity. Studies have demonstrated that early referral to a nephrologist can be life-saving and can also markedly improve quality of life. Besides recommending treatments for CKD, early referral can assist in medication management and in minimizing exposure to potential nephrotoxins. In patients who progress to end-stage renal disease, having an established patient-PCP-nephrologist relationship can ease the transition to renal replacement therapy or transplantation.

Socioeconomic status, psychosocial factors, race and nocturnal blood pressure dipping in a Hispanic cohort

BACKGROUND

Little information is available about the relationship of socioeconomic status (SES) to blunted nocturnal ambulatory blood pressure (ABP) dipping among Hispanics and whether this relationship differs by race. We sought to characterize ABP nondipping and its determinants in a sample of Hispanics.

METHODS

We enrolled 180 Hispanic participants not on antihypertensive medications. SES was defined by years of educational attainment. All participants underwent 24-hour ABP monitoring. A decrease of <10% in the ratio between average awake and average asleep systolic BP was considered nondipping.

RESULTS

The mean age of the cohort was 67.1 ± 8.7, mean educational level was 9.4 ± 4.4 years, and 58.9% of the cohort was female. The cohort was comprised of 78.3% Caribbean Hispanics with the rest from Mexico and Central/South America; 41.4% self-identified as white Hispanic, 34.4% self-identified as black Hispanic, and 24.4% did not racially self- identify. The percentage of nondippers was 57.8%. Educational attainment (10.5 years vs. 8.6 years; P <0.01) was significantly higher among dippers than nondippers. In multivariable analyses, each 1-year increase in education was associated with a 9% reduction in the likelihood of being a nondipper (odds ratio [OR], 0.91; 95% confidence interval [CI], 0.84-0.98; P = 0.01). There were significantly greater odds of being a nondipper for black Hispanics than for white Hispanics (OR, 2.83, 95% CI, 1.29-6.23; P = 0.005). Higher SES was significantly protective of nondipping in white Hispanics but not black Hispanics.

CONCLUSIONS

These results document a substantial prevalence of nondipping in a cohort of predominantly normotensive Hispanics. Dipping status varied significantly by race. Lower SES is significantly associated with nondipping status, and race potentially impacts on this relation.

Are there consequences of labeling patients with prehypertension? An experimental study of effects on blood pressure and quality of life

OBJECTIVE

The prehypertension classification was introduced to facilitate prevention efforts among patients at increased risk for hypertension. Although patients who have been told that they have hypertension report worse outcomes than unaware hypertensives, little is known about whether or not prehypertension labeling has negative effects. We evaluated the effects of labeling individuals with prehypertension on blood pressure and health-related quality of life three months later.

METHODS

One hundred adults (aged 19 to 82 [mean=40.0] years; 54% women; 64% racial/ethnic minorities) with screening blood pressure in the prehypertensive range (120-139/80-89 mmHg) and no history of diagnosis or treatment of elevated blood pressure were randomly assigned to either a "Labeled" group in which they were informed of their prehypertension, or an "Unlabeled" group in which they were not informed. Subjects underwent office blood pressure measurement, 24-hour ambulatory blood pressure monitoring and completed self-report questionnaires at baseline and at three months.

RESULTS

Multilevel mixed effects regression analyses indicated that changes in the white coat effect, office blood pressure, mean daytime ambulatory blood pressure, and physical and mental health did not differ significantly between the two groups. Adjusting for age, sex, race/ethnicity and body mass index did not affect the results.

CONCLUSION

These findings suggest that labeling patients with prehypertension does not have negative effects on blood pressure or quality of life. Additional research is needed to develop approaches to communicating with patients about their blood pressure that will maximize the clinical and public health impact of the prehypertension classification.