The association of leptin and incident hypertension in the reasons for geographic and racial differences in stroke (REGARDS) cohort.

Leptin is an adipokine associated with obesity and with hypertension in animal models. Whether leptin is associated with hypertension independent of obesity is unclear. Relative to White adults, Black adults have higher circulating leptin concentration. As such, leptin may mediate some of the excess burden of incident hypertension among Black adults. REGARDS enrolled 30,239 adults aged ≥45 years from 48 US states in 2003-07. Baseline leptin was measured in a sex- and race-stratified sample of 4400 participants. Modified Poisson regression estimated relative risk (RR) of incident hypertension (new ≥140/≥90 mmHg threshold or use of antihypertensives) per SD of log-transformed leptin, stratified by obesity (BMI of 30 kg/m2). Inverse odds ratio weighting estimated the % mediation by leptin of the excess hypertension RR among Black relative to White participants. Among the 1821 participants without prevalent hypertension, 35% developed incident hypertension. Obesity modified the relationship between leptin and incident hypertension (P-interaction 0.006) such that higher leptin was associated with greater hypertension risk in the crude model among those with BMI < 30 kg/m2, but not those with BMI ≥ 30 kg/m2. This was fully attenuated when adjusting for anthropometric measures. In the crude model, Black adults had a 52% greater risk of incident hypertension. Leptin did not significantly mediate this disparity. In this national U.S. sample, leptin was associated with incident hypertension among non-obese but not obese adults. Future investigations should focus on the effect of weight modification on incident hypertension among non-obese adults with elevated leptin.

Clinical Impact of 3- versus 5-Minute Delay and 30- versus 60-Second Intervals on Unattended Automated Office Blood Pressure Measurements.

BACKGROUND: Guidelines advise automated office blood pressure (AOBP) with an initial 5-minute delay and multiple measurements at least 60 seconds apart. Recent studies suggest that AOBP may be accurate with shorter delays or intervals, but evidence in clinical settings is limited. METHODS: Patients referred to one hypertension (HTN) center underwent 24-hour ambulatory blood pressure monitoring (ABPM) and one of four non-randomized, unattended AOBP protocols: a 3- or 5-minute delay with a 30 or 60-second interval, i.e., 3 min/30 sec/30 sec, 3/60/60, 5/30/30 and 5/60/60 protocols. HTN was defined as systolic blood pressure ≥140 or diastolic blood pressure ≥90 mmHg. RESULTS: We compared differences in mean blood pressure and HTN classification between average AOBP and awake-time ABPM by t-tests and Fisher's exact test. Among 212 participants (mean 58.9 years, 61% women, 25% Black), there was substantial overlap in the probability distributions of awake-time ABPM and each of the three AOBP measures. Systolic blood pressure means were similar between the 5/60/60 and 3/30/30 protocols and 5/30/30 and 3/60/60 protocols. The 5/30/30 was associated with a higher proportion of systolic HTN, while the 3/60/60 protocol was associated with a higher proportion of diastolic HTN. There were no significant differences in systolic or diastolic HTN between 5/60/60 and 3/30/30 protocols with respect to awake-time ABPM. CONCLUSIONS: In this quality improvement study, the shortest AOBP protocol did not differ significantly from the longest protocol. The time savings of shorter protocols may improve AOBP adoption in clinical practice without meaningfully compromising accuracy.

Telehealth versus self-directed lifestyle intervention to promote healthy blood pressure: a protocol for a randomised controlled trial.

INTRODUCTION: Weight loss, consumption of a Dietary Approaches to Stop Hypertension dietary pattern, reduced sodium intake and increased physical activity have been shown to lower blood pressure (BP). Use of web-based tools and telehealth to deliver lifestyle counselling could be potentially scalable solutions to improve BP through behavioural modification though limited data exists to support these approaches in clinical practice. METHODS AND ANALYSIS: This randomised controlled trial will compare the efficacy of a telehealth versus self-directed lifestyle intervention in lowering 24-hour SBP in patients with overweight/obesity (body mass index ≥25 kg/m2) and 24-hour SBP 120-160 mm Hg. All participants receive personalised recommendations to improve dietary quality based on a web-based Food Frequency Questionnaire, access to an online comprehensive weight management programme and a smartphone dietary app. The telehealth arm additionally includes weekly calls with registered dietitian nutritionists who use motivational interviewing. The primary outcome is change from baseline to 12 weeks in 24-hour SBP. Secondary outcomes include changes from baseline in 24-hour diastolic BP, daytime SBP, nighttime SP, daytime diastolic BP, nighttime diastolic BP, total Healthy Eating Index-2015 score, weight, waist circumference and physical activity. Other prespecified outcomes will include change in individual components of the Healthy Eating Index-2015 score, and satisfaction with the Healthy BP research study measured on a 5-point Likert scale. ETHICS AND DISSEMINATION: The study has been approved by the Geisinger Institutional Review Board. Results will be disseminated through peer-reviewed publications and conference presentations. TRIAL REGISTRATION NUMBER: NCT03700710.

Effects of dietary carbohydrate on 1,5-anhydroglucitol in a population without diabetes: results from the OmniCarb trial.

AIMS: To determine the effects of dietary changes in amount and type of carbohydrate on 1,5-anhydroglucitol levels. METHODS: We conducted an ancillary study to a completed, randomized clinical trial in overweight and obese adults without diabetes (N=159). Using a crossover design, participants were fed each one of four diets in turn for 5 weeks, with 2-week washout periods inbetween. The four diets were: high glycaemic index (≥65) with high proportion of carbohydrate (58% kcal) (GC); low glycaemic index (GI≤45) with low proportion of carbohydrate (40% kcal) (gc); low glycaemic index with high proportion of carbohydrate (gC); and high glycaemic index with low proportion of carbohydrate (Gc). Plasma 1,5-anhydroglucitol levels were measured at baseline and after each feeding period. RESULTS: At baseline, participants had a mean age of 53 years (53% women, 52% non-Hispanic black, 50% obese). Their mean fasting glucose and 1,5-anhydroglucitol levels were 97 mg/dl (5.4 mmol/l) and 18.6 µg/mL (113.3 µmol/l), respectively. Compared with baseline, each of the four diets reduced 1,5-anhydroglucitol by a range of -2.4 to -3.7 µg/mL (-14.6 to -22.5 µmol/l); all P <0.001). Reducing either glycaemic index or proportion of carbohydrate lowered 1,5-anhydroglucitol levels. These effects were additive, such that reducing both glycaemic index and proportion of carbohydrates decreased 1,5-anhydroglucitol by -1.31 µg/mL [95% CI: -1.63, -0.99; P<0.001 or -8.0 (-9.9, -6.0) µmol/l]. Furthermore, these effects were confirmed in a subgroup of participants with 12-h glucose monitoring and no documented hyperglycaemia (fasting glucose <160 mg/dl or 8.9 mmol/l). CONCLUSIONS: Both type and amount of dietary carbohydrate affect 1,5-anhydroglucitol plasma concentrations in adults without diabetes. This finding contradicts the long-standing notion that 1,5-anhydroglucitol remains at constant concentrations in the blood in the absence of hyperglycaemic excursions. (Clinical trials registry number: NCT00051350).