From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions.

This study aimed to evaluate the reproducibility of office (OBP), ambulatory (ABP), and home blood pressure (HBP) measurements in children and adolescents, and their implications in diagnosing hypertension in clinical practice and in pediatric hypertension research. Apparently healthy children and adolescents referred for suspected hypertension were included. Measurements of 2-visit OBP, 7-day HBP, and 24-hour ABP were performed twice, 1 to 6 months apart. Reproducibility was quantified using the SD of differences between repeated measurements. The sample size of clinical trials comparing the efficacy of antihypertensive drugs using each method was calculated. Fifty-eight individuals were analyzed (mean age, 13.0±2.9 years, 60.3% boys). The reproducibility of 24-hour ABP (SD of differences 5.7/4.5 systolic/diastolic) and HBP (5.9/5.0 mm Hg) were comparable and superior to that of visit-2 OBP (9.2/7.8) and awake (6.7/5.5) or asleep ABP (7.6/6.1). As a consequence, a parallel-group comparative trial aiming to detect a difference in the effect of 2 drugs of 10 mm Hg systolic BP, would require 36 participants when using OBP measurements, 14 using 24-hour ABP, and 15 using HBP (102/34/42 respectively for detecting a 5 mm Hg difference in diastolic BP). For a crossover design trial, the corresponding sample sizes are 9/3/4 for systolic BP and 26/9/11 for diastolic, respectively. These data suggest that in children and adolescents 24-hour ABP and 7-day HBP have similar reproducibility, superior to OBP and daytime or asleep ABP. These findings have major implications in diagnosing hypertension in children in clinical practice and in designing clinical research trials in pediatric hypertension.

This study attempted to investigate the behavior of 24-hour central ambulatory blood pressure (ABP) in adolescents and young adults. Adolescents and young adults (age 10-25 years) referred for elevated blood pressure (BP) and healthy volunteers had simultaneous 24-hour peripheral (brachial) and central (aortic) ABP monitoring using the same automated upper-arm cuff device (Mobil-O-Graph 24h PWA). Central BP was calculated by the device using two different calibration methods (C1SBP using peripheral systolic (pSBP)/diastolic BP and C2SBP using mean arterial/diastolic BP). A total of 136 participants (age 17.9 ± 4.7 years, 54% adolescents, 77% males, 25% volunteers, 34% with elevated peripheral ABP) were analyzed. Twenty-four-hour pSBP was higher than C1SBP, with this difference being more pronounced during daytime than nighttime (16.3 ± 4.5 and 10.5 ± 3.2 mm Hg, respectively, P < .001). Younger age, higher body height, and male gender were associated with greater systolic ABP amplification (pSBP-C1SBP difference). C1SBP followed the variation pattern of pSBP, yet with smaller nighttime dip (8.4 ± 6.0% vs 11.9 ± 4.6%, P < .001), whereas C2SBP increased (2.4 ± 7.2%) during nighttime sleep (P < .001 for comparison with pSBP change). Older age remained independent determinant of larger nighttime BP fall for pSBP and C1SBP, whereas male gender predicted a larger nighttime C2SBP rise. These data suggest that the calibration method of the BP monitor considerably influences the diurnal variation in central BP, showing a lesser nocturnal dip than pSBP or even nocturnal BP rise, which are determined by the individual's age and gender.

Carotid-femoral pulse wave velocity (cfPWV) is the gold standard method for assessing arterial stiffness. This study evaluated automated brachial-ankle PWV (baPWV) taken by a professional oscillometric blood pressure monitor (Microlife WatchBP Office Vascular) versus reference cfPWV (Complior device). Subjects recruited from a hypertension outpatient clinic had duplicate baPWV and cfPWV measurements (randomized crossover design) and carotid ultrasonography. Of 102 subjects recruited, 101 had valid baPWV measurements. Four subjects were excluded and 97 were analyzed (age 58.3 ± 11.4 years, men 70%, hypertensives 76%, diabetics 17%, cardiovascular disease 10%, smokers 23%). The mean difference between baPWV (13.1 ± 1.8 m/s) and cfPWV (9.1 ± 1.8 m/s) was 4.0 ± 1.4 m/s (P < .01) with close association between them (r = 0.70, P < .01). baPWV and cfPWV were correlated with age (r 0.54/0.49 respectively), systolic blood pressure (0.45/0.50), carotid intima-media thickness (0.31/0.44), and carotid distensibility coefficient (-0.47/-0.34) (all P < .05; no difference between the two methods, z test). There was reasonable agreement (77%) between the two methods in identifying subjects at the top quartile of their distributions (kappa 0.39, P < .01). The areas under the receiver operating characteristic curves for the identification of carotid plaques were comparable for cfPWV and baPWV (0.79 and 0.74 respectively, P = NS). Automated baPWV measurement by a professional oscillometric blood pressure monitor is feasible and observer-independent. baPWV values differ from those by cfPWV, yet they are closely correlated, have reasonable agreement in detecting increased arterial stiffness and give similar associations with carotid stiffness and atherosclerosis.

High blood pressure (BP) is a highly prevalent modifiable cause of cardiovascular disease, stroke, and death. Accurate BP measurement is critical, given that a 5-mmHg measurement error may lead to incorrect hypertension status classification in 84 million individuals worldwide. This position statement summarizes procedures for optimizing observer performance in clinic BP measurement, with special attention given to low-tomiddle- income settings, where resource limitations, heavy workloads, time constraints, and lack of electrical power make measurement more challenging. Many measurement errors can be minimized by appropriate patient preparation and standardized techniques. Validated semi-automated/automated upper arm cuff devices should be used instead of auscultation to simplify measurement and prevent observer error. Task sharing, creating a dedicated measurement workstation, and using semi-automated or solar-charged devices may help. Ensuring observer training, and periodic re-training, is critical. Low-cost, easily accessible certification programs should be considered to facilitate best BP measurement practice.