Long-term effects of weight-reducing diets in hypertensive patients

Resistant hypertension: consensus document from the Korean society of hypertension

Although reports vary, the prevalence of true resistant hypertension and apparent treatment-resistant hypertension (aTRH) has been reported to be 10.3% and 14.7%, respectively. As there is a rapid increase in the prevalence of obesity, chronic kidney disease, and diabetes mellitus, factors that are associated with resistant hypertension, the prevalence of resistant hypertension is expected to rise as well. Frequently, patients with aTRH have pseudoresistant hypertension [aTRH due to white-coat uncontrolled hypertension (WUCH), drug underdosing, poor adherence, and inaccurate office blood pressure (BP) measurements]. As the prevalence of WUCH is high among patients with aTRH, the use of out-of-office BP measurements, both ambulatory blood pressure monitoring (ABPM) and home blood pressure monitoring (HBPM), is essential to exclude WUCH. Non-adherence is especially problematic, and methods to assess adherence remain limited and often not clinically feasible. Therefore, the use of HBPM and higher utilization of single-pill fixed-dose combination treatments should be emphasized to improve drug adherence. In addition, primary aldosteronism and symptomatic obstructive sleep apnea are quite common in patients with hypertension and more so in patients with resistant hypertension. Screening for these diseases is essential, as the treatment of these secondary causes may help control BP in patients who are otherwise difficult to treat. Finally, a proper drug regimen combined with lifestyle modifications is essential to control BP in these patients.

Lifestyle Medicine as a Treatment for Resistant Hypertension

PURPOSE OF REVIEW

Approximately 10% of the adults with hypertension fail to achieve the recommended blood pressure treatment targets on 3 antihypertensive medications or require ≥ 4 medications to achieve goal. These patients with 'resistant hypertension' have an increased risk of target organ damage, adverse clinical events, and all-cause mortality. Although lifestyle modification is widely recommended as a first-line approach for the management of high blood pressure, the effects of lifestyle modifications in patients with resistant hypertension has not been widely studied. This review aims to provide an overview of the emerging evidence on the benefits of lifestyle modifications in patients with resistant hypertension, reviews potential mechanisms by which lifestyles may reduce blood pressure, and discusses the clinical implications of the recent findings in this field.

RECENT FINDINGS

Evidence from single-component randomized clinical trials demonstrated that aerobic exercise, weight loss and dietary modification can reduce clinic and ambulatory blood pressure in patients with resistant hypertension. Moreover, evidence from multi-component trials involving exercise and dietary modification and weight management can facilitate lifestyle change, reduce clinic and ambulatory blood pressure, and improve biomarkers of cardiovascular risk. This new evidence supports the efficacy of lifestyle modifications added to optimized medical therapy in reducing blood pressure and improving cardiovascular risk biomarkers in patients with resistant hypertension. These findings need to be confirmed in larger studies, and the persistence of benefit over extended follow-up needs further study.

Feasibility of Low-Sodium, High-Potassium Processed Foods and Their Effect on Blood Pressure in Free-Living Japanese Men: A Randomized, Double-Blind Controlled Trial

We aimed to verify the effect of new low-sodium high-potassium seasonings and processed foods containing poly-γ-glutamic acid on blood pressure in free-living settings. To this end, we conducted a randomized, double-blind controlled trial on 187 Japanese men, aged 35–67 years, who did not use antihypertensives. Participants were randomly allocated to an intervention (n = 93) or a control group (n = 94). They were given a boxed lunch and miso soup (average Na and K content for the intervention group: 1175 and 1476 mg; for the control group: 2243 and 703 mg, respectively). Blood pressure was measured three times every morning for 1 week immediately before and during the final week of the trial. On the day before and the final day of the intervention period, 24 h urine samples were collected. After intervention, the intervention group showed a significantly stronger decrease in the urinary sodium-to-potassium ratio than the control group (p < 0.001). The mean difference in systolic blood pressure change after adjustment for baseline values between the two groups was −2.1 (95% CI: −3.6, −0.6) mmHg. Compliance between the groups was similar, suggesting successful blinding. In conclusion, the use of new seasonings and processed foods aimed at lowering blood pressure in free-living settings may be feasible and effective.

Physical Activity and Sedentary Behavior in Cardiac Rehabilitation: Does Body Mass Index Matter?

OBJECTIVE

The purpose of this study was to investigate the relationship between body mass index (BMI) class and physical activity and sedentary behavior in patients with acute coronary syndrome (ACS) during cardiac rehabilitation (CR).

METHODS

This study was a secondary analysis of the OPTICARE trial. Physical activity and sedentary behavior were measured in participants with ACS (n = 359) using actigraphy at baseline, directly after completion of a multidisciplinary 12-week exercise-based CR program and 9 months thereafter. Outcome measures were step count and duration of time (percentage of wear time) spent in light physical activity, moderate-to-vigorous physical activity, and sedentary behavior. Participants were classified as normal weight (BMI = 18.5-24.99 kg/m2; n = 82), overweight (BMI = 25.0-29.99 kg/m2; n = 182), or obese (BMI ≥ 30.0 kg/m2; n = 95). Linear mixed-effects models were applied to study the relationship between BMI class and physical activity and sedentary behavior.

RESULTS

At the start of CR, compared with participants with normal weight, participants with obesity made on average 1.11 steps fewer per minute (952 steps/d), spent 2.9% (25 min/d) less time in light physical activity, and spent 3.31% (28 min/d) more time in sedentary behavior. Participants of all BMI classes improved their physical activity and sedentary behavior levels similarly during CR, and these improvements were maintained after completion of CR.

CONCLUSION

Participants with ACS who had obesity started CR with a less favorable physical activity and sedentary behavior profile than that of participants with normal weight. Because all BMI classes showed similar improvement during CR, this deficit was preserved.

IMPACT

This study indicates that reconsideration of the CR program in the Netherlands for patients with ACS and obesity is warranted, and development of more inclusive interventions for specific populations is needed. A new program for people with obesity should include added counseling on increasing physical activity and preventing sedentary behavior to facilitate weight loss and reduce mortality risk.

LAY SUMMARY

People with ACS who have obesity are less active and sit more than individuals with normal weight, both during and after CR. This study suggests that CR needs to be changed to help individuals increase their physical activity to help them lose weight and reduce their risk of death.

Long-term effects of weight-reducing diets in people with hypertension

BACKGROUND

All major guidelines for antihypertensive therapy recommend weight loss. Dietary interventions that aim to reduce body weight might therefore be a useful intervention to reduce blood pressure and adverse cardiovascular events associated with hypertension.

OBJECTIVES

Primary objectives To assess the long-term effects of weight-reducing diets in people with hypertension on all-cause mortality, cardiovascular morbidity, and adverse events (including total serious adverse events, withdrawal due to adverse events, and total non-serious adverse events). Secondary objectives To assess the long-term effects of weight-reducing diets in people with hypertension on change from baseline in systolic blood pressure, change from baseline in diastolic blood pressure, and body weight reduction.

SEARCH METHODS

For this updated review, the Cochrane Hypertension Information Specialist searched the following databases for randomised controlled trials up to April 2020: the Cochrane Hypertension Specialised Register, CENTRAL (2020, Issue 3), Ovid MEDLINE, Ovid Embase, and ClinicalTrials.gov. We also contacted authors of relevant papers about further published and unpublished work. The searches had no language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of at least 24 weeks' duration that compared weight-reducing dietary interventions to no dietary intervention in adults with primary hypertension.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed risks of bias and extracted data. Where appropriate and in the absence of significant heterogeneity between studies (P > 0.1), we pooled studies using a fixed-effect meta-analysis. In case of moderate or larger heterogeneity as measured by Higgins I2, we used a random-effects model.

MAIN RESULTS

This second review update did not reveal any new trials, so the number of included trials remains the same: eight RCTs involving a total of 2100 participants with high blood pressure and a mean age of 45 to 66 years. Mean treatment duration was 6 to 36 months. We judged the risks of bias as unclear or high for all but two trials. No study included mortality as a predefined outcome. One RCT evaluated the effects of dietary weight loss on a combined endpoint consisting of the necessity of reinstating antihypertensive therapy and severe cardiovascular complications. In this RCT, weight-reducing diet lowered the endpoint compared to no diet: hazard ratio 0.70 (95% confidence interval (CI) 0.57 to 0.87). None of the trials evaluated adverse events as designated in our protocol. The certainty of the evidence was low for a blood pressure reduction in participants assigned to weight-loss diets as compared to controls: systolic blood pressure: mean difference (MD) -4.5 mm Hg (95% CI -7.2 to -1.8 mm Hg) (3 studies, 731 participants), and diastolic blood pressure: MD -3.2 mm Hg (95% CI -4.8 to -1.5 mm Hg) (3 studies, 731 participants). We judged the certainty of the evidence to be high for weight reduction in dietary weight loss groups as compared to controls: MD -4.0 kg (95% CI -4.8 to -3.2) (5 trials, 880 participants). Two trials used withdrawal of antihypertensive medication as their primary outcome. Even though we did not consider this a relevant outcome for our review, the results of these RCTs strengthen the finding of a reduction of blood pressure by dietary weight-loss interventions.

AUTHORS' CONCLUSIONS

In this second update, the conclusions remain unchanged, as we found no new trials. In people with primary hypertension, weight-loss diets reduced body weight and blood pressure, but the magnitude of the effects are uncertain due to the small number of participants and studies included in the analyses. Whether weight loss reduces mortality and morbidity is unknown. No useful information on adverse effects was reported in the relevant trials.

Improving obesity and blood pressure

Obesity-associated hypertension is a serious public health concern. Sympathetic nervous system (SNS) overactivity, especially in the kidneys, is an important mechanism linking obesity to hypertension. Some adipokines play important roles in elevating blood pressure (BP). Hyperinsulinemia caused by insulin resistance stimulates sodium reabsorption, enhances sodium retention, and increases circulating plasma volume. Hyperinsulinemia also stimulates both the renin-angiotensin-aldosterone system (RAAS) and the SNS, resulting in the acceleration of atherosclerosis through the hypertrophy of vascular smooth muscle cells, which contributes to increased peripheral vascular resistance. Obesity is associated with increased RAAS activity despite volume overload, as the tissue RAASs are stimulated in obese hypertensive individuals. Mineralocorticoid receptor-associated hypertension must also be considered in obese patients with resistant hypertension. Obstructive sleep apnea syndrome (OSAS) is the most common cause of secondary hypertension. Some components of the gut microbiota contribute to BP control; therefore, gut dysbiosis caused by obesity might lead to increased BP. The ratio of visceral fat to subcutaneous fat is higher in Japanese patients than in Caucasian patients, which may explain why Japanese patients are more susceptible to metabolic disorders even though they are less obese than Caucasian individuals. Obesity-associated kidney dysfunction directly increases BP, leading to further deterioration of kidney function. A bodyweight reduction of more than 3% or 5 kg significantly lowers BP. Gastrointestinal bypass surgery is an effective treatment for morbid obesity and its related metabolic disorders, including hypertension. Because both obesity and hypertension are representative lifestyle-related disorders, lifestyle modification, especially to improve obesity, should be performed first as a treatment for hypertension.

Inhibition of the sodium-glucose co-transporter 2 in the elderly: clinical and mechanistic insights into safety and efficacy

The prevalence of type 2 diabetes mellitus (T2DM) in the elderly grew sharply over the last decade. Reduced insulin sensitivity and secretory capacity, weight gain, sarcopenia, and elevated adiposity are all common metabolic and body changes in the aging population that favor an increased risk of hypoglycemia, frailty syndrome, falls, and cognitive dysfunction. First line antidiabetic therapy is frequently not safe in older individuals because of its high risk of hypoglycemia and prevalent co-morbid diseases, such as chronic kidney disease, osteoporosis, cardiovascular disease, and obesity. Sodium-glucose cotransporter 2 inhibitor (SGLT2i) is a new class of antidiabetic therapy that inhibits glucose and sodium reabsorption on renal proximal convoluted tubule. Its effect is well demonstrated in various clinical scenarios in the younger population. This review and metanalysis describe particularities of the SGLT2i on the elderly, with mechanistic insights of the potential benefit and remaining challenges about the use of these drugs in this important age group. Further, we will present a meta-analysis of the main effects of SGLT2i reported in post-hoc studies in which the median age of the subgroups analyzed was over 60 years. Despite the absence of specific clinical trials for this population, our findings suggest that SGLT2i therapy on older individuals is effective to lower glucose and maintain its effect on systolic blood pressure and body weight.

Decreases in adiposity reduce the risk of hypertension: Results from a prospective cohort of adolescents

This study aimed to evaluate the effect of age-related changes in body mass index and waist circumference during adolescence on blood pressure levels and incidence of hypertension. Among the 2159 adolescents recruited at 13 years in Porto, Portugal, we evaluated those free of hypertension at baseline and followed-up at 17 years (n = 1377) - EPITeen cohort, 2003-2008. Changes in BMI percentage (BMI%) and waist circumference percentage (WC%) were evaluated continuously as the difference between 13 and 17 years, then categorized in sex-specific quartiles. Hypertension was defined as systolic and/or diastolic blood pressure ≥ 95th sex- age- and height-specific reference percentile. The association between changes in adiposity and incidence of hypertension was computed through generalized linear models with log link function and Poisson distribution [incidence rate ratios (IRR), 95% confidence intervals (95%CI)], adjusting for baseline adiposity, sex, and family history of hypertension. Overall incidence rate of hypertension was 23.8 (95%CI 19.6-28.8) per 1000 person-years. Participants presenting the highest decrease in BMI% from 13 to 17 years (1st quartile) presented lower SBP at 17y, while for those with increasing BMI% (4th quartile) SBP increased. In comparison to stable BMI% (3rd quartile), decreases in BMI% (1st quartile) were associated with 44% lower risk of hypertension at 17y (IRR = 0.56, 95%CI 0.32-0.97). Increases in BMI% (4th quartile) were associated with increased incidence, although without statistical significance (IRR = 1.11, 95%CI 0.66-1.85). Results were similar when considering changes in WC%. Decreases in BMI and WC throughout adolescence in the whole spectrum of adiposity levels presented potential benefit for blood pressure.

Impact of sodium-glucose cotransporter 2 inhibitors on blood pressure

SGLT2 inhibitors are glucose-lowering agents used to treat type 2 diabetes mellitus (T2DM). These agents target the kidney to promote urinary glucose excretion, resulting in improved blood glucose control. SGLT2-inhibitor therapy is also associated with weight loss and blood pressure (BP) lowering. Hypertension is a common comorbidity in patients with T2DM, and is associated with excess morbidity and mortality. This review summarizes data on the effect of SGLT2 inhibitors marketed in the US (namely canagliflozin, dapagliflozin, or empagliflozin) on BP in patients with T2DM. Boolean searches were conducted that included terms related to BP or hypertension with terms for SGLT2 inhibitors, canagliflozin, dapagliflozin, or empagliflozin using PubMed, Google, and Google Scholar. Data from numerous randomized controlled trials of SGLT2 inhibitors in patients with T2DM demonstrated clinically relevant reductions in both systolic and diastolic BP, assessed via seated office measurements and 24-hour ambulatory BP monitoring. Observed BP lowering was not associated with compensatory increases in heart rate. Circadian BP rhythm was also maintained. The mechanism of SGLT2 inhibitor-associated BP reduction is not fully understood, but is assumed to be related to osmotic diuresis and natriuresis. Other factors that may also contribute to BP reduction include SGLT2 inhibitor-associated decreases in body weight and reduced arterial stiffness. Local inhibition of the renin-angiotensin-aldosterone system secondary to increased delivery of sodium to the juxtaglomerular apparatus during SGLT2 inhibition has also been postulated. Although SGLT2 inhibitors are not indicated as BP-lowering agents, the modest decreases in systolic and diastolic BP observed with SGLT2 inhibitors may provide an extra clinical advantage for the majority of patients with T2DM, in addition to improving blood glucose control.

Applying for, reviewing and funding public health research in Germany and beyond

Public health research is complex, involves various disciplines, epistemological perspectives and methods, and is rarely conducted in a controlled setting. Often, the added value of a research project lies in its inter- or trans-disciplinary interaction, reflecting the complexity of the research questions at hand. This creates specific challenges when writing and reviewing public health research grant applications. Therefore, the German Research Foundation (DFG), the largest independent research funding organization in Germany, organized a round table to discuss the process of writing, reviewing and funding public health research. The aim was to analyse the challenges of writing, reviewing and granting scientific public health projects and to improve the situation by offering guidance to applicants, reviewers and funding organizations. The DFG round table discussion brought together national and international public health researchers and representatives of funding organizations. Based on their presentations and discussions, a core group of the participants (the authors) wrote a first draft on the challenges of writing and reviewing public health research proposals and on possible solutions. Comments were discussed in the group of authors until consensus was reached. Public health research demands an epistemological openness and the integration of a broad range of specific skills and expertise. Applicants need to explicitly refer to theories as well as to methodological and ethical standards and elaborate on why certain combinations of theories and methods are required. Simultaneously, they must acknowledge and meet the practical and ethical challenges of conducting research in complex real life settings. Reviewers need to make the rationale for their judgments transparent, refer to the corresponding standards and be explicit about any limitations in their expertise towards the review boards. Grant review boards, funding organizations and research ethics committees need to be aware of the specific conditions of public health research, provide adequate guidance to applicants and reviewers, and ensure that processes and the expertise involved adequately reflect the topic under review.

Long-term effects of weight-reducing diets in people with hypertension

BACKGROUND

All major guidelines for antihypertensive therapy recommend weight loss. Thus dietary interventions that aim to reduce body weight might be a useful intervention to reduce blood pressure and adverse cardiovascular events associated with hypertension.

OBJECTIVES

Primary objectivesTo assess the long-term effects of weight-reducing diets in people with hypertension on all-cause mortality, cardiovascular morbidity, and adverse events (including total serious adverse events, withdrawal due to adverse events, and total non-serious adverse events). Secondary objectivesTo assess the long-term effects of weight-reducing diets in people with hypertension on change from baseline in systolic blood pressure, change from baseline in diastolic blood pressure, and body weight reduction.

SEARCH METHODS

We obtained studies from computerised searches of the Cochrane Central Register of Controlled Trials (CENTRAL), the Cochrane Hypertension Specialised Register, Ovid MEDLINE, and Ovid EMBASE, and from searches in reference lists, systematic reviews, and the clinical trials registry ClinicalTrials.gov (status as of 2 February 2015).

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of at least 24 weeks' duration that compared weight-reducing dietary interventions to no dietary intervention in adults with primary hypertension.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed risk of bias and extracted data. We pooled studies using fixed-effect meta-analysis. In case of moderate or larger heterogeneity as measured by Higgins I(2), we used a random-effects model.

MAIN RESULTS

This review update did not reveal any new studies, so the number of included studies remained the same: 8 studies involving a total of 2100 participants with high blood pressure and a mean age of 45 to 66 years. Mean treatment duration was 6 to 36 months. We judged the risk of bias as unclear or high for all but two trials. No study included mortality as a predefined outcome. One RCT evaluated the effects of dietary weight loss on a combined endpoint consisting of the necessity of reinstating antihypertensive therapy and severe cardiovascular complications. In this RCT, weight-reducing diet lowered the endpoint compared to no diet: hazard ratio 0.70 (95% confidence interval (CI), 0.57 to 0.87). None of the studies evaluated adverse events as designated in our protocol. There was low-quality evidence for a blood pressure reduction in participants assigned to weight loss diets as compared to controls: systolic blood pressure: mean difference (MD) -4.5 mm Hg (95% CI -7.2 to -1.8 mm Hg) (3 of 8 studies included in analysis), and diastolic blood pressure: MD -3.2 mm Hg (95% CI -4.8 to -1.5 mm Hg) (3 of  8  studies included in analysis). There was moderate-quality evidence for weight reduction in dietary weight loss groups as compared to controls: MD -4.0 kg (95% CI -4.8 to -3.2) (5 of 8 studies included in analysis). Two studies used withdrawal of antihypertensive medication as their primary outcome. Even though we did not consider this a relevant outcome for our review, the results of these studies strengthen the finding of reduction of blood pressure by dietary weight loss interventions.

AUTHORS' CONCLUSIONS

In this update, the conclusions remain the same, as we found no new trials. In people with primary hypertension, weight loss diets reduced body weight and blood pressure, however the magnitude of the effects are uncertain due to the small number of participants and studies included in the analyses. Whether weight loss reduces mortality and morbidity is unknown. No useful information on adverse effects was reported in the relevant trials.

Intentional Weight Loss and Longevity in Overweight Patients with Type 2 Diabetes: A Population-Based Cohort Study

Objective

This study examined the influence of weight loss on long-term morbidity and mortality in overweight (BMI≥25kg/m²) patients with type 2 diabetes, and tested the hypothesis that therapeutic intentional weight loss supervised by a medical doctor prolongs life and reduces the risk for cardiovascular disease in these patients.

Methods

This is a 19 year cohort study of patients in the intervention arm of the randomized clinical trial Diabetes Care in General Practice. Weight and prospective intentions for weight loss were monitored every third month for six years in 761 consecutive patients (≥40 years) newly diagnosed with diabetes in general practices throughout Denmark in 1989–92. Multivariable Cox regression was used to estimate the association between weight change during the monitoring period (year 0 to 6) and the outcomes during the succeeding 13 years (year 6 to 19) in 444 patients who were overweight at diagnosis and alive at the end of the monitoring period (year 6). The analysis was adjusted for age, sex, education, BMI at diagnosis, change in smoking, change in physical activity, change in medication, and the Charlson comorbidity 6-year score. Outcomes were from national registers.

Results

Overall, weight loss regardless of intention was an independent risk factor for increased all-cause mortality (P<0.01). The adjusted hazard ratio for all-cause mortality, cardiovascular mortality, and cardiovascular morbidity attributable to an intentional weight loss of 1 kg/year was 1.20 (95%CI 0.97–1.50, P = 0.10), 1.26 (0.93–1.72, P = 0.14), and 1.06 (0.79–1.42, P = 0.71), respectively. Limiting the analysis to include only those patients who survived the first 2 years after the monitoring period did not substantially change these estimates. A non-linear spline estimate indicated a V-like association between weight change and all-cause mortality, suggesting the best prognosis for those who maintained their weight.

Conclusions

In this population-based cohort of overweight patients with type 2 diabetes, successful therapeutic intentional weight loss, supervised by a doctor over six years, was not associated with reduced all-cause mortality or cardiovascular morbidity/mortality during the succeeding 13 years.

Obesity is associated with race/sex disparities in diabetes and hypertension prevalence, but not cardiovascular disease, among HIV-infected adults

Race/sex differences are observed in cardiometabolic disease (CMD) risk and prevalence in the context of treated, chronic HIV infection, and these differences could be exacerbated by disparities in obesity prevalence. We sought to determine the effect of obesity on these disparities among people living with HIV. Prevalence of CMD (dyslipidemia, cardiovascular disorders, hypertension, diabetes, chronic kidney disease) was determined for patients seen at the University of Alabama at Birmingham HIV clinic between 7/2010 and 6/2011. Staged logistic regression was used to examine the impact of race/sex on comorbidities adjusting for key confounders including/excluding obesity (body mass index ≥30 kg/m(2)). Of 1,800 participants, 77% were male, 54% were black, and 25% were obese. Obesity prevalence differed by race/sex: black women 49%, black men 24%, white women 24%, white men 15% (p<0.01). Compared to white men, other groups had reduced odds for dyslipidemia and cardiovascular disorders (p<0.01). Black men had increased odds for hypertension and chronic kidney disease, while black women had a nearly 2-fold increased odds for diabetes and hypertension (all at p<0.01). The associations of black women with diabetes and hypertension were attenuated when obesity was included in the models. Other group differences remained significant. Disparities in obesity prevalence do not explain race/sex differences in all CMD among people with HIV. Obesity accounted for associations with diabetes/hypertension for black women, who may benefit from weight reduction to decrease disease risk. Further investigations into the etiology and treatment of CMD in people living with HIV should consider unique race/sex treatment issues.

An assessment of randomized controlled trials (RCTs) for non-communicable diseases (NCDs): more and higher quality research is required in less developed countries

Research is crucial to implement evidence-based health interventions for control of non-communicable diseases (NCDs). This study aims to assess main features of randomized controlled trials (RCTs) for control of NCDs, and to identify gaps in clinical research on NCDs between high-income and less developed countries. The study included 1177 RCTs in 82 Cochrane Systematic reviews (CSRs) and evaluated interventions for adults with hypertension, diabetes, stroke, or heart diseases. Multivariate logistic regression analyses were conducted to explore factors associated with risk of bias in included RCTs. We found that 78.2% of RCTs of interventions for major NCDs recruited patients in high-income countries. The number of RCTs included in the CSRs was increasing over time, and the increasing speed was more noticeable for RCTs conducted in middle-income countries. RCTs conducted in less developed countries tended to be more recently published, less likely to be published in English, with smaller sample sizes, and at a higher risk of bias. In conclusion, there is still a lack of research evidence for control of NCDs in less developed countries. To brace for rising NCDs and avoid waste of scarce research resources, not only more but also higher quality clinical trials are required in low-and-middle-income countries.

Lost in translation: dietary management of cardiovascular risk factors is seldom implemented

OBJECTIVE

To assess dietary management of cardiovascular risk factors (CVRFs) in the general population.

METHOD

Cross-sectional study conducted between 2009 and 2012 on 4811 participants (2567 women, 58±11years) living in Lausanne, Switzerland.

RESULTS

Sixteen percent of participants diagnosed with overweight/obesity reported a slimming diet. Slimming diet was associated with diagnosis of hypertension: Odds ratio and (95% confidence interval): 0.61 (0.40-0.93); older age [0.84 (0.58-1.21), 0.79 (0.53-1.18) and 0.47 (0.27-0.81) for [50-60[, [60-70[ and [70+ years, respectively]; female gender [1.84 (1.36-2.48)] and diagnosis of diabetes [2.16 (1.13-4.12)]. Only 8% of participants diagnosed with hypertension reported a low-salt diet. Low-salt diet was associated with antihypertensive drug treatment [2.17 (1.28-3.68)] and diagnosis of diabetes [2.72 (1.26-5.86)]. One-third of participants diagnosed with dyslipidemia reported a low-fat diet. Low-fat diet was associated with female gender [1.47 (1.17-1.86)]; older age [1.29 (0.89-1.87), 1.71 (1.18-2.48) and 2.01 (1.33-3.03) for [50-60[, [60-70[ and [70+ years, respectively]; hypolipidemic drug treatment [OR=1.68 (1.29-2.18)]; current smoking [0.70 (0.51-0.96)] and obesity [0.67 (0.45-1.00)]. Approximately half of participants diagnosed with diabetes reported an antidiabetic diet. Antidiabetic diet was associated with current smoking [0.44 (0.22-0.88)] and antidiabetic drug treatment [OR=3.26 (1.81-5.86)].

CONCLUSION

Dietary management of CVRFs is seldom implemented in Switzerland.

Age- and sex-specific causal effects of adiposity on cardiovascular risk factors

Observational studies have reported different effects of adiposity on cardiovascular risk factors across age and sex. Since cardiovascular risk factors are enriched in obese individuals, it has not been easy to dissect the effects of adiposity from those of other risk factors. We used a Mendelian randomization approach, applying a set of 32 genetic markers to estimate the causal effect of adiposity on blood pressure, glycemic indices, circulating lipid levels, and markers of inflammation and liver disease in up to 67,553 individuals. All analyses were stratified by age (cutoff 55 years of age) and sex. The genetic score was associated with BMI in both nonstratified analysis (P = 2.8 × 10(-107)) and stratified analyses (all P < 3.3 × 10(-30)). We found evidence of a causal effect of adiposity on blood pressure, fasting levels of insulin, C-reactive protein, interleukin-6, HDL cholesterol, and triglycerides in a nonstratified analysis and in the <55-year stratum. Further, we found evidence of a smaller causal effect on total cholesterol (P for difference = 0.015) in the ≥55-year stratum than in the <55-year stratum, a finding that could be explained by biology, survival bias, or differential medication. In conclusion, this study extends previous knowledge of the effects of adiposity by providing sex- and age-specific causal estimates on cardiovascular risk factors.

Altered dietary salt intake for people with chronic kidney disease

BACKGROUND

Salt intake shows great promise as a modifiable risk factor for reducing heart disease incidence and delaying kidney function decline in people with chronic kidney disease (CKD). However, a clear consensus of the benefits of reducing salt in people with CKD is lacking.

OBJECTIVES

This review evaluated the benefits and harms of altering dietary salt intake in people with CKD.

SEARCH METHODS

We searched the Cochrane Renal Group's Specialised Register to 13 January 2015 through contact with the Trials' Search Co-ordinator using search terms relevant to this review.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared two or more levels of salt intake in people with any stage of CKD.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed studies for eligibility and conducted risk of bias evaluation. Results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes, and mean difference (MD) and 95% CI for continuous outcomes. Mean effect sizes were calculated using the random-effects models.

MAIN RESULTS

We included eight studies (24 reports, 258 participants). Because duration of the included studies was too short (1 to 26 weeks) to test the effect of salt restriction on endpoints such as mortality, cardiovascular events or CKD progression, changes in salt intake on blood pressure and other secondary risk factors were applied. Three studies were parallel RCTs and five were cross-over studies. Selection bias was low in five studies and unclear in three. Performance and detection biases were low in two studies and unclear in six. Attrition and reporting biases were low in four studies and unclear in four. One study had the potential for high carryover effect; three had high risk of bias from baseline characteristics (change of medication or diet) and two studies were industry funded.There was a significant reduction in 24 hour sodium excretion associated with low salt interventions (range 52 to 141 mmol) (8 studies, 258 participants: MD -105.86 mmol/d, 95% CI -119.20 to -92.51; I(2) = 51%). Reducing salt intake significantly reduced systolic blood pressure (8 studies, 258 participants: MD -8.75 mm Hg, 95% CI -11.33 to -6.16; I(2) = 0%) and diastolic blood pressure (8 studies, 258 participants: MD -3.70 mm Hg, 95% CI -5.09 to -2.30; I(2) = 0%). One study reported restricting salt intake reduced the risk of oedema by 56%. Salt restriction significantly increased plasma renin activity (2 studies, 71 participants: MD 1.08 ng/mL/h, 95% CI 0.51 to 1.65; I(2) = 0%) and serum aldosterone (2 studies, 71 participants: 6.20 ng/dL (95% CI 3.82 to 8.58; I(2) = 0%). Antihypertensive medication dosage was significantly reduced with a low salt diet (2 studies, 52 participants): RR 5.48, 95% CI 1.27 to 23.66; I(2) = 0%). There was no significant difference in eGFR (2 studies, 68 participants: MD -1.14 mL/min/1.73 m(2), 95% CI -4.38 to 2.11; I(2) = 0%), creatinine clearance (3 studies, 85 participants): MD -4.60 mL/min, 95% CI -11.78 to 2.57; I(2) = 0%), serum creatinine (5 studies, 151 participants: MD 5.14 µmol/L, 95% CI -8.98 to 19.26; I(2) = 59%) or body weight (5 studies, 139 participants: MD -1.46 kg; 95% CI -4.55 to 1.64; I(2) = 0%). There was no significant change in total cholesterol in relation to salt restriction (3 studies, 105 participants: MD -0.23 mmol/L, 95% CI -0.57 to 0.10; I(2) = 0%) or symptomatic hypotension (2 studies, 72 participants: RR 6.60, 95% CI 0.77 to 56.55; I(2) = 0%). Salt restriction significantly reduced urinary protein excretion in all studies that reported proteinuria as an outcome, however data could not be meta-analysed.

AUTHORS' CONCLUSIONS

We found a critical evidence gap in long-term effects of salt restriction in people with CKD that meant we were unable to determine the direct effects of sodium restriction on primary endpoints such as mortality and progression to end-stage kidney disease (ESKD). We found that salt reduction in people with CKD reduced blood pressure considerably and consistently reduced proteinuria. If such reductions could be maintained long-term, this effect may translate to clinically significant reductions in ESKD incidence and cardiovascular events. Research into the long-term effects of sodium-restricted diet for people with CKD is warranted, as is investigation into adherence to a low salt diet.

Years of life lost and healthy life-years lost from diabetes and cardiovascular disease in overweight and obese people: a modelling study

BACKGROUND

Despite the increased risk of cardiovascular disease and type 2 diabetes associated with excess bodyweight, development of a clinically meaningful metric for health professionals remains a challenge. We estimated the years of life lost and the life-years lost from diabetes and cardiovascular disease associated with excess bodyweight.

METHODS

We developed a disease-simulation model to estimate the annual risk of diabetes, cardiovascular disease, and mortality for people with BMI of 25-<30 kg/m(2) (overweight), 30-<35 kg/m(2) (obese), or 35 kg/m(2) and higher (very obese), compared with an ideal BMI of 18·5-<25 kg/m(2). We used data from 3992 non-Hispanic white participants in the National Nutrition and Examination Survey (2003-10) for whom complete risk factor data and fasting glucose concentrations were available. After validation of the model projections, we estimated the years of life lost and healthy life-years lost associated with each bodyweight category.

FINDINGS

Excess bodyweight was positively associated with risk factors for cardiovascular disease and type 2 diabetes. The effect of excess weight on years of life lost was greatest for young individuals and decreased with increasing age. The years of life lost for obese men ranged from 0·8 years (95% CI 0·2-1·4) in those aged 60-79 years to 5·9 years (4·4-7·4) in those aged 20-39 years, and years lost for very obese men ranged from 0·9 (0-1·8) years in those aged 60-79 years to 8·4 (7·0-9·8) years in those aged 20-39 years, but losses were smaller and sometimes negligible for men who were only overweight. Similar results were noted for women (eg, 6·1 years [4·6-7·6] lost for very obese women aged 20-39 years; 0·9 years [0·1-1·7] lost for very obese women aged 60-79 years). Healthy life-years lost were two to four times higher than total years of life lost for all age groups and bodyweight categories.

INTERPRETATION

Our estimations for both healthy life-years and total years of life lost show the effect of excess bodyweight on cardiovascular disease and diabetes, and might provide a useful health measure for discussions between health professionals and their patients.

FUNDING

Canadian Institutes of Health Research.

Treatment for overweight and obesity in adult populations: a systematic review and meta-analysis

BACKGROUND

Obesity is a major public health issue. This review updates the evidence on the effectiveness of behavioural and pharmacologic treatments for overweight and obesity in adults.

METHODS

We updated the search conducted in a previous review. Randomized trials of primary-care-relevant behavioural (diet, exercise and lifestyle) and pharmacologic (orlistat and metformin) with or without behavioural treatments in overweight and obese adults were included if 12-month, postbaseline data were provided for weight outcomes. Studies reporting harms were included regardless of design. Data were extracted and pooled wherever possible for 5 weight outcomes, 6 secondary health outcomes and 4 adverse events categories.

RESULTS

We identified 68 studies, most consisted of short-term (≤ 12 mo) treatments using diet (n = 8), exercise (n = 4), diet and exercise (n = 10), lifestyle (n = 19), orlistat (n = 25) or metformin (n = 4). Compared with the control groups, intervention participants had a greater weight loss of -3.02 kg (95% confidence interval [CI] -3.52 to -2.52), a greater reduction in waist circumference of -2.78 cm (95% CI -3.34 to -2.22) and a greater reduction in body mass index of -1.11 kg/m(2) (95% CI -1.39 to -0.84). The relative risk for loss of ≥ 5% body weight was 1.77 (95% CI 1.58-1.99, [number needed to treat 5, 95% CI 4-7]), and the relative risk for loss of ≥ 10% body weight was 1.91 (95% CI 1.69-2.16, [number needed to treat 9, 95% CI 7-12]). Incidence of type 2 diabetes was lower among pre-diabetic intervention participants (relative risk 0.62 [95% CI 0.50-0.77], number needed to treat 17 [95% CI 13-29]). With prevalence rates for type 2 diabetes on the rise, weight loss coupled with a reduction in the incidence of type 2 diabetes could potentially have a significant benefit on population health and a possible reduction in need for drug treatments for glycemic control.

INTERPRETATION

There is moderate quality evidence that behavioural and pharmacologic plus behvioural, treatments for overweight and obesity in adults lead to clinically important reductions in weight and incidence of type 2 diabetes in pre-diabetic populations.

REGISTRATION

PROSPERO no. CRD42012002753.

The long-term coronary heart disease risk of previously obese patients with type 2 diabetes mellitus

BACKGROUND

Obesity is associated with insulin resistance, development of diabetes, and coronary heart disease. There is limited information on the contribution of previous obesity on the risk of coronary heart disease. We aimed to examine the effect of previous history of obesity on the occurrence of coronary heart disease in patients with diabetes.

METHODS

We carried out a retrospective chart analysis of 315 type 2 diabetic patients without obesity and without atherosclerotic cardiovascular events at their initial hospital visit (men/women 236/79; mean ± standard deviation; age 53.1 ± 6.6 years; maximal body mass index before enrollment (MAXBMI) 26.6 ± 3.4 kg/m2; decrease of the BMI at enrollment from MAXBMI (deltaBMI) 4.23 ± 2.62 kg/m2) to investigate the association of previous obesity (MAXBMI larger than 30 kg/m2) with the long-term incidence of cardiovascular events. Of 315 patients, forty-eight were previously obese.

RESULTS

After median follow-up of 13.9 years, 48 patients developed coronary heart disease. The Kaplan-Meier analysis exhibited that coronary heart disease occurred more frequently in previously obese patients than in subjects in the reference category (22 kg/m2 < or = MAXBMI < 25 kg/m2) and that the effect lasted proportionally over follow-up periods. Multivariate Cox regression models showed that hazard ratios and corresponding 95% confidence intervals of coronary heart disease for patients with previous obesity compared with subjects in the reference category were 2.52 and 1.15 to 5.50 (p value = 0.020) after adjustment for age, sex, smoking status, systolic blood pressure, total cholesterol and HDL cholesterol. In this cohort, deltaBMI strongly correlated with MAXBMI and also behaved as a risk factor. The hazard ratios and 95% confidence intervals by the increment of one standard deviation of deltaBMI after adjustment for age, sex, smoking status, systolic blood pressure, total cholesterol and HDL cholesterol were 1.38 and 1.08 to 1.79 (p value = 0.013).

CONCLUSIONS

Previous obesity and/or large body weight loss before admission might act as an increased risk for coronary heart disease.

New advances in models and strategies for developing anti-obesity drugs

INTRODUCTION

Obesity is a worldwide pandemic. Obesity-related health and economic costs are staggering. Existing strategies to combat obesity through lifestyle improvements and medical intervention have had limited success. Pharmacotherapy, in combination with lifestyle modification, may play a vital role in reversing the disease burden. However, past and current weight-loss medications have had serious safety risks, notably cardiovascular and psychiatric events.

AREAS COVERED

The authors review the strategies for designing new anti-obesity drugs by describing those currently in development. They describe their target, mechanism of action and developmental or regulatory status. Furthermore, they discuss the problem of weight regain following weight loss, and its relevance to the long-term success of anti-obesity pharmacotherapy.

EXPERT OPINION

For weight management drugs to achieve the safety and efficacy required to be impactful, current studies are uncovering and characterizing new targets, including new signaling circuits and hormones regulating appetite and metabolism, and re-evaluating the role of pharmacotherapy in weight management. To avoid the safety failures of many past weight-loss drugs, the models and strategies covered in this article incorporate recent advances in knowledge and technology. We discuss the emergence of cGMP signaling as a potentially transformative target in weight management. Modulating cGMP signaling may represent an ideal goal for an anti-obesity pharmacotherapy, reflecting some of the major themes described in the present review: targeting pathways that are newly realized as relevant for weight management; promoting safety by re-purposing drugs that are safe, proven, and approved for clinical use; and having a synergistic effect on multiple, reinforcing pathways.

A low-carbohydrate/high-fat diet reduces blood pressure in spontaneously hypertensive rats without deleterious changes in insulin resistance

Previous studies reported that diets high in simple carbohydrates could increase blood pressure in rodents. We hypothesized that the converse, a low-carbohydrate/high-fat diet, might reduce blood pressure. Six-week-old spontaneously hypertensive rats (SHR; n = 54) and Wistar-Kyoto rats (WKY; n = 53, normotensive control) were fed either a control diet (C; 10% fat, 70% carbohydrate, 20% protein) or a low-carbohydrate/high-fat diet (HF; 20% carbohydrate, 60% fat, 20% protein). After 10 wk, SHR-HF had lower (P < 0.05) mean arterial pressure than SHR-C (148 ± 3 vs. 159 ± 3 mmHg) but a similar degree of cardiac hypertrophy (33.4 ± 0.4 vs. 33.1 ± 0.4 heart weight/tibia length, mg/mm). Mesenteric arteries and the entire aorta were used to assess vascular function and endothelial nitric oxide synthase (eNOS) signaling, respectively. Endothelium-dependent (acetylcholine) relaxation of mesenteric arteries was improved (P < 0.05) in SHR-HF vs. SHR-C, whereas contraction (potassium chloride, phenylephrine) was reduced (P < 0.05). Phosphorylation of eNOSSer1177 increased (P < 0.05) in arteries from SHR-HF vs. SHR-C. Plasma glucose, insulin, and homoeostatic model of insulin assessment were lower (P < 0.05) in SHR-HF vs. SHR-C, whereas peripheral insulin sensitivity (insulin tolerance test) was similar. After a 10-h fast, insulin stimulation (2 U/kg ip) increased (P < 0.05) phosphorylation of AktSer473 and S6 in heart and gastrocnemius similarly in SHR-C vs. SHR-HF. In conclusion, a low-carbohydrate/high-fat diet reduced blood pressure and improved arterial function in SHR without producing signs of insulin resistance or altering insulin-mediated signaling in the heart, skeletal muscle, or vasculature.

A randomised trial of a weight loss intervention for overweight and obese people diagnosed with coronary heart disease and/or type 2 diabetes

BACKGROUND

Weight reduction limits disease progression in obese people with coronary heart disease (CHD) and/or type 2 diabetes mellitus (T2DM).

PURPOSE

To test a 16-week group-based weight reduction intervention combining exercise, diet and behaviour change strategies aimed to increase self-efficacy (Healthy Eating and Exercise Lifestyle Program-HEELP) on weight, body mass index (BMI), waist circumference and exercise.

METHODS

Participants with CHD and/or T2DM and BMI between 27 to 39 kg/m(2) were randomised to HEELP (n=83) or usual care (n=65).

RESULTS

Participants were aged a mean 63.47 years (SD 8.9), male (58 %) and Caucasian (79 %). HEELP participants lost significantly more weight, BMI and waist circumference and exercised more days/week for a longer duration/week than usual care. Clinically significant weight loss (≥5 %) was more common in HEELP than usual care.

CONCLUSION

The HEELP resulted in weight loss and improved exercise behaviour in obese people with CHD and T2DM.

Neuropeptide Y promoter polymorphism modifies effects of a weight-loss diet on 2-year changes of blood pressure: the preventing overweight using novel dietary strategies trial

Neuropeptide Y (NPY) is implicated in the regulation of blood pressure (BP), and NPY pathways in the hypothalamus are sensitive to dietary fat. We evaluated the potential effect of a functional variant rs16147 located in the NPY gene promoter region on the association between 2-year diet intervention and change in multiple BP measures in the randomized Preventing Overweight Using Novel Dietary Strategies Trial. The NPY rs16147 was genotyped in 723 obese adults who were randomly assigned to 1 of 4 diets differing in the target percentages of energy derived from fat, protein, and carbohydrate. The changes of 4 BP phenotypes, including systolic BP, diastolic BP, pulse pressure, and mean arterial pressure, during 2-year diet intervention were analyzed. In the total participants and participants with hypertension, we observed significant and consistent interactions between rs16147 genotype and dietary fat intake on changes in multiple BP phenotypes at 2 years (all P for interactions <0.05). The risk allele (C allele) was associated with a greater reduction of BP phenotypes in response to low-fat diet, whereas an opposite genetic effect was observed in response to high-fat diet. In addition, the C allele was related to greater changes in 4 BP phenotypes in hypertensive compared with nonhypertensive participants. Our data suggest that NPY rs16147 may modulate the association between dietary fat intake and changes in BP phenotypes, and the C allele exerts a long-term beneficial effect on lowering BP in response to low-fat diet in obese and hypertensive subjects.