Crystal C. Tyson

Cell phone Intervention for You (CITY): A randomized, controlled trial of behavioral weight loss intervention for young adults using mobile technology

To determine the effect on weight of two mobile technology‐based (mHealth) behavioral weight loss interventions in young adults.

Weight loss intervention for young adults using mobile technology: design and rationale of a randomized controlled trial – Cell phone Intervention for You (CITY)

BACKGROUND The obesity epidemic has spread to young adults, leading to significant public health implications later in adulthood. Intervention in early adulthood may be an effective public health strategy for reducing the long-term health impact of the epidemic. Few weight loss trials have been conducted in young adults. It is unclear what weight loss strategies are beneficial in this population. PURPOSE To describe the design and rationale of the NHLBI-sponsored Cell Phone Intervention for You (CITY) study, which is a single center, randomized three-arm trial that compares the impact on weight loss of 1) a behavioral intervention that is delivered almost entirely via cell phone technology (Cell Phone group); and 2) a behavioral intervention delivered mainly through monthly personal coaching calls enhanced by self-monitoring via cell phone (Personal Coaching group), each compared to 3) a usual care, advice-only control condition. METHODS A total of 365 community-dwelling overweight/obese adults aged 18-35 years were randomized to receive one of these three interventions for 24 months in parallel group design. Study personnel assessing outcomes were blinded to group assignment. The primary outcome is weight change at 24 [corrected] months. We hypothesize that each active intervention will cause more weight loss than the usual care condition. Study completion is anticipated in 2014. CONCLUSIONS If effective, implementation of the CITY interventions could mitigate the alarming rates of obesity in young adults through promotion of weight loss. ClinicalTrial.gov: NCT01092364.

Impact of 5-year weight change on blood pressure: Results from the weight loss maintenance trial

In this secondary analysis of the Weight Loss Maintenance trial, the authors assessed the relationship between blood pressure (BP) change and weight change in overweight and obese adults with hypertension and/or dyslipidemia who were randomized to 1 of 3 weight loss maintenance strategies for 5 years. The participants were grouped (N=741) based on weight change from randomization to 60 months as: (1) weight loss, (2) weight stable, or (3) weight gain. A significant positive correlation between weight change and systolic BP (SBP) change at 12, 30, and 60 months and between weight change and diastolic BP (DBP) change at 30 months was observed. From randomization to 60 months, mean SBP increased to a similar degree for the weight gain group (4.2±standard error=0.6 mm Hg; P<.001) and weight stable group (4.6±1.1 mm Hg; P<.001), but SBP did not rise in the weight loss group (1.0±1.7 mm Hg, P=.53). DBP was unchanged for all groups at 60 months. Although aging may have contributed to rise in BP at 60 months, it does not appear to fully account for observed BP changes. These results suggest that continued modest weight loss may be sufficient for long‐term BP lowering.

Adaptive intervention design in mobile health: Intervention design and development in the Cell Phone Intervention for You trial.

Background/aims: The obesity epidemic has spread to young adults, and obesity is a significant risk factor for cardiovascular disease. The prominence and increasing functionality of mobile phones may provide an opportunity to deliver longitudinal and scalable weight management interventions in young adults. The aim of this article is to describe the design and development of the intervention tested in the Cell Phone Intervention for You study and to highlight the importance of adaptive intervention design that made it possible. The Cell Phone Intervention for You study was a National Heart, Lung, and Blood Institute–sponsored, controlled, 24-month randomized clinical trial comparing two active interventions to a usual-care control group. Participants were 365 overweight or obese (body mass index ≥ 25 kg/m2) young adults. Methods: Both active interventions were designed based on social cognitive theory and incorporated techniques for behavioral self-management and motivational enhancement. Initial intervention development occurred during a 1-year formative phase utilizing focus groups and iterative, participatory design. During the intervention testing, adaptive intervention design, where an intervention is updated or extended throughout a trial while assuring the delivery of exactly the same intervention to each cohort, was employed. The adaptive intervention design strategy distributed technical work and allowed introduction of novel components in phases intended to help promote and sustain participant engagement. Adaptive intervention design was made possible by exploiting the mobile phone’s remote data capabilities so that adoption of particular application components could be continuously monitored and components subsequently added or updated remotely. Results: The cell phone intervention was delivered almost entirely via cell phone and was always-present, proactive, and interactive—providing passive and active reminders, frequent opportunities for knowledge dissemination, and multiple tools for self-tracking and receiving tailored feedback. The intervention changed over 2 years to promote and sustain engagement. The personal coaching intervention, alternatively, was primarily personal coaching with trained coaches based on a proven intervention, enhanced with a mobile application, but where all interactions with the technology were participant-initiated. Conclusion: The complexity and length of the technology-based randomized clinical trial created challenges in engagement and technology adaptation, which were generally discovered using novel remote monitoring technology and addressed using the adaptive intervention design. Investigators should plan to develop tools and procedures that explicitly support continuous remote monitoring of interventions to support adaptive intervention design in long-term, technology-based studies, as well as developing the interventions themselves.

Association of a reduction in central obesity and phosphorus intake with changes in urinary albumin excretion: the PREMIER study.

BACKGROUND Excess adiposity and dietary factors may be important determinants of urinary albumin excretion (UAE). STUDY DESIGN Observational analysis of PREMIER, a randomized trial designed to lower blood pressure using behavioral interventions (counseling on weight loss, healthy diet, and exercise). SETTING & PARTICIPANTS 481 participants with normal kidney function who provided adequate 24-hour urine collections at baseline and 6 months. PREDICTORS Change in waist circumference; 24-hour urine sodium, potassium, and phosphorus excretion; and protein intake estimated from urea nitrogen. OUTCOMES & MEASUREMENTS The primary outcome was change in log-transformed 24-hour UAE over 6 months. RESULTS After 6 months, the proportion of individuals with UAE ≥10 mg/d decreased from 18.7% to 12.7% (P < 0.001). Changes in mean waist circumference (-4.2 ± 6.6 [SD] cm), 24-hour excretion of sodium (-28.2 ± 71.7 mmol/d), potassium (+8.4 ± 27.8 mmol/d), phosphorus (-27.7 ± 314.1 mg/d), and protein intake (-1.7 ± 19.4 g/d) were observed. After adjustment for relevant covariates, the following variables were associated significantly with reduction in ln(UAE) in separate models: decrease in waist circumference (P = 0.001), decrease in 24-hour urine phosphorus excretion (P < 0.001), and decrease in protein intake (P = 0.01). In a multivariable model including these 3 predictors, decreases in waist circumference (P = 0.002) and 24-hour urine phosphorus excretion (P = 0.03), but not change in protein intake (P = 0.5), remained associated significantly with reduction in ln(UAE). These associations remained significant even after adjustment for changes in blood pressure and insulin resistance. Baseline UAE and metabolic syndrome modified the relationship of waist circumference with ln(UAE); specifically, individuals with higher UAE and baseline metabolic syndrome experienced greater reductions in ln(UAE) from decreases in waist circumference. LIMITATIONS Observational study with potential for confounding. CONCLUSIONS In adults with normal kidney function, decreases in waist circumference and 24-hour urine phosphorus excretion are associated with reductions in UAE. These findings support the rationale for clinical trials to determine whether reducing dietary phosphorus intake or waist circumference could prevent chronic kidney disease or slow its progression.

The Dietary Approaches to Stop Hypertension (DASH) Eating Pattern in Special Populations

The Dietary Approaches to Stop Hypertension (DASH) trial showed that a diet rich in fruits, vegetables, low-fat dairy products with reduced total and saturated fat, cholesterol, and sugar-sweetened products effectively lowers blood pressure in individuals with prehypertension and stage I hypertension. Limited evidence is available on the safety and efficacy of the DASH eating pattern in special patient populations that were excluded from the trial. Caution should be exercised before initiating the DASH diet in patients with chronic kidney disease, chronic liver disease, and those who are prescribed renin-angiotensin-aldosterone system antagonist, but these conditions are not strict contraindications to DASH. Modifications to the DASH diet may be necessary to facilitate its use in patients with chronic heart failure, uncontrolled diabetes mellitus type II, lactose intolerance, and celiac disease. In general, the DASH diet can be adopted by most patient populations and initiated simultaneously with medication therapy and other lifestyle interventions.

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.

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.

Apparent Treatment-Resistant Hypertension and Chronic Kidney Disease: Another Cardiovascular-Renal Syndrome?

To identify patients at increased risk of cardiovascular (CV) outcomes, apparent treatment-resistant hypertension (aTRH) is defined as having a blood pressure above goal despite the use of 3 or more antihypertensive therapies of different classes at maximally tolerated doses, ideally including a diuretic. Recent epidemiologic studies in selected populations estimated the prevalence of aTRH as 10% to 15% among patients with hypertension and that aTRH is associated with elevated risk of CV and renal outcomes. Additionally, aTRH and CKD are associated. Although the pathogenesis of aTRH is multifactorial, the kidney is believed to play a significant role. Increased volume expansion, aldosterone concentration, mineralocorticoid receptor activity, arterial stiffness, and sympathetic nervous system activity are central to the pathogenesis of aTRH and are targets of therapies. Although diuretics form the basis of therapy in aTRH, pathophysiologic and clinical data suggest an important role for aldosterone antagonism. Interventional techniques, such as renal denervation and carotid baroreceptor activation, modulate the sympathetic nervous system and are currently in phase III trials for the treatment of aTRH. These technologies are as yet unproven and have not been investigated in relationship to CV outcomes or in patients with CKD.

Impact of Kidney Function on Effects of the Dietary Approaches to Stop Hypertension (Dash) Diet.

Objectives Although the Dietary Approaches to Stop Hypertension (DASH) diet lowers blood pressure in adults with hypertension, how kidney function impacts this effect is not known. We evaluated whether Estimated Glomerular Filtration Rate (eGFR) modifies the effect of the DASH diet on blood pressure, markers of mineral metabolism, and markers of kidney function. Methods Secondary analysis of the DASH-Sodium trial, a multicenter, randomized, controlled human feeding study that evaluated the blood pressure lowering effect of the DASH diet at three levels of sodium intake. Data from 92 participants with pre-hypertension or stage 1 hypertension during the 3450 mg /day sodium diet assignment contributed to this analysis. Stored frozen plasma and urine specimens were used to measure kidney related laboratory outcomes. Results Effects of the DASH diet on blood pressure, phosphorus, intact parathyroid hormone, creatinine, and albuminuria were not modified by baseline eGFR (mean 84.5 ± 18.0 ml/min/1.73 m2, range 44.1 to 138.6 ml/min/1.73 m2) or the presence of chronic kidney disease (N=13%). Conclusions The impact of the DASH diet on blood pressure, markers of mineral metabolism, and markers of kidney function does not appear to be modified by eGFR in this small subset of DASH-Sodium trial participants with relatively preserved kidney function. Whether greater reduction in eGFR modifies the effects of DASH on kidney related measures is yet to be determined. A larger study in individuals with more advanced kidney disease is needed to establish the efficacy and safety of the DASH diet in this patient population.