The influence of sexual maturation on blood pressure and body fatness in African‐American adolescent girls and boys

To examine the influence of sexual maturation (SM) on blood pressure (BP) and body fatness during puberty among African‐American children. Longitudinal data were collected from 283 African‐American children aged 9–15 years over a 1.5‐year period. Measured anthropometric measures included height, weight, skinfold thickness, waist circumference (WC), and systolic and diastolic BP (SBP/DBP) at baseline, 1‐year, and 1.5‐year follow‐up were used. SM was assessed using self‐reported Tanner stages (range 1–5) at baseline. Spearman correlation and regression analyses were conducted to test associations between study variables. Early maturing girls had higher BP and body mass index (BMI = weight (kg)/height (m)²) at follow‐up than nonearly maturing girls (SBP: 117.4 vs. 111.7; DBP: 66.3 vs. 60.7; BMI: 27.7 vs. 23.5; all P < 0.05, respectively). Baseline Tanner stage was positively associated with follow‐up SBP (r = 0.28), DBP (r = 0.37), BMI (r = 0.45), skinfold thickness (r = 0.37), and WC (r = 0.40) in girls, but not in boys. The influence of SM on BP independent of body size was tested via several different multiple linear regression models by adding measures of body size and their changes (height and BMI) between baseline and follow‐up. Early maturing girls had higher SBP and DBP (β = 4.30, P < 0.05; β = 3.28, P < 0.05; respectively) and BMI (β = 1.69, P < 0.05) at 1.5‐year follow‐up than their counterparts. In boys, a marginally significant reverse association (β = ?1.05 to ?1.19) between SM stages and DBP was detected. SM affects BP and body fatness in girls, and should be considered in assessment of BP and obesity in adolescents. Am. J. Hum. Biol., 2009. © 2008 Wiley‐Liss, Inc.     

The effect of menarcheal age on anthropometric,limb length,and bone measures in Hutterite and non‐Hutterite women

The age women reach menarche may affect bone length and mass. Some studies show an earlier menarcheal age (MA) results in a shorter stature and increased body fat. We hypothesized that Hutterite women have a shorter height and limb length, but greater bone mass and areal bone mineral density (aBMD) than non‐Hutterites. Results are from a secondary analysis of 344 (198 Hutterite) healthy, pre‐menopausal women aged 20?40 years who participated in the South Dakota Rural Bone Health Study. Bone measures were obtained by DXA (spine, hip and total body) and pQCT (4 and 20% distal radius). MA correlated with year of birth (r = ?0.10, P = 0.08) indicating a trend toward a younger MA for women born in more recent years. MA was inversely associated with current weight (r = ?0.11, P < 0.05), percent body fat (r = ?0.16, P < 0.01), femoral neck BMC (r = ?0.18, P = 0.003), femoral neck aBMD (r = ?0.21, P < 0.001), hip aBMD (r = ?0.22, P < 0.001) and trabecular volumetric BMD (vBMD) (r = ?0.14, P = 0.03). Hutterite women had a younger MA than non‐Hutterite women (12.3 ± 1.3 vs. 13.0 ± 1.3 yr, P < 0.001). In final regression models controlling for diet and activity patterns, Hutterite compared to non‐Hutterite women had shorter standing height (162 ± 0.4 vs. 166 ± 0.4 cm, P < 0.001), forearm length (258 ± 0.8 vs. 261 ± 0.9 mm, P = 0.04); and leg length (76 ± 0.2 vs. 77 ± 0.3 cm, P < 0.01) as hypothesized, but MA did not predict these outcomes. In conclusion, younger MA in Hutterite women did not explain their shorter standing height and limb lengths, but total hip aBMD was inversely associated with MA and greater in Hutterite than non‐Hutterite women. Am. J. Hum. Biol., 2008. © 2008 Wiley‐Liss, Inc.     

Thermoregulatory sympathetic nervous system activity and diet‐induced waist‐circumference reduction in obese Japanese women

The present study is designed to investigate how and to what extent sympathovagal behavior in a balanced low‐calorie diet relates to favorable changes of body mass, waist circumference, and/or metabolic risk factors. The study involved 28 mildly obese women without clinical complications, who underwent an 8‐week calorie restriction program using a 1,200‐kcal daily diet with an adequate nutrient content; including two regular meals, and one formula meal replacement. All subjects were examined before and after the dietary intervention. We measured anthropometric parameters, blood pressure, and biochemical blood profiles for lipid metabolism. Autonomic nervous system activity was evaluated by heart rate variability power spectral analysis. The dietary intervention induced moderate, but significant reduction of waist circumference (?5.3% ± 0.8%), body fat percentage (?5.8% ± 0.8%), and body mass (?6.6% ± 0.5%). Linear regression analysis showed that Δvery low frequency (VLF) power reflecting energy metabolic‐ and thermoregulatory sympathetic function significantly correlated to Δwaist circumference (r = ?0.53, P < 0.01), Δbody fat percentage (r = ?0.39, P < 0.05), Δbody mass (r = ?0.43, P < 0.05), ΔHDL‐cholesterol/total cholesterol ratio (HDL‐C/TC) (r = 0.62, P < 0.001), and Δnonesterified fatty acids (NEFA) (r = 0.56, P < 0.01). A stepwise multiple regression analysis additionally revealed that Δwaist circumference (P = 0.024), ΔHDL‐C/TC (P = 0.013), and ΔNEFA (P = 0.016) were significant and independent factors, which contributing to the variance in ΔVLF power (r² = 0.61). Although causes and consequences of obesity continue to elude researchers, the present study indicates that thermoregulatory sympathetic activity relates to moderate waist‐circumference reduction together with favorable changes of blood lipid profiles after short‐term dietary modification in mildly obese women. Am. J. Hum. Biol. 2009. © 2009 Wiley‐Liss, Inc.     

Gender Differences in the Association between Serum γ-Glutamyltransferase and Blood Pressure Change: A Prospective Community-Based Cohort Study

We evaluated the gender differences in the relation of baseline serum γ-glutamyltransferase (GGT) levels to blood pressure (BP) change during 4 yr. 4,025 normotensive subjects (1,945 men and 2,080 women) who aged 40-69 yr at baseline participated in the Ansung-Ansan cohort of the Korean Genome Epidemiology Study were included. The associations of GGT with baseline BP or 4-yr change of BP were evaluated. GGT levels were associated with systolic blood pressure (SBP) and diastolic blood pressure (DBP) at baseline after adjusting for age, body mass index (BMI), HDL-cholesterol, triglyceride, C-reactive protein (CRP), current smoking status and alcohol intake (SBP, β=1.28, P<0.001; DBP, β=1.41, P<0.001). GGT levels were also associated with 4-yr change in BP after adjusting for age, BMI, HDL-cholesterol, triglyceride, CRP, current smoking status, alcohol intake and SBP (SBP, β=1.08, P=0.001; DBP, β=0.64, P=0.003). This association was statistically significant in men (SBP, β=1.82, P<0.001; DBP, β=1.05, P=0.001), but not in women (SBP, β=0.38, P=0.466; DBP, β=-0.37, P=0.304). Remarkably, this association between GGT and BP was significant in men at 40-49 yr of age. In summary, we found positive associations between GGT levels at baseline and the change of BP. The relation of GGT level and the change of BP was only significant in men, not in women, which warrants further studies to elucidate the biologic mechanisms.

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Telomere length and LINE1 methylation is associated with chromosomal aberrations in peripheral blood

The frequency of chromosomal aberrations in peripheral blood predicts a probable cancer risk. The individual telomere length and methylation of repetitive elements may be susceptibility factors for chromosomal aberrations. A cohort of healthy Norwegian men (N = 364) recruited during 1980–1999 were analyzed for chromosomal aberrations in phytohemagglutinin‐stimulated lymphocytes from peripheral blood. Chromosome‐type or chromatid‐type aberrations were scored. DNA was extracted from slides cytogenetically analyzed and relative average telomere length and methylation of LINE1 repeats were determined by quantitative polymerase chain reaction and bisulfite pyrosequencing, respectively. Information about individuals with malignant tumors (N = 49) diagnosed after chromosomal aberrations testing until end of 2008 was obtained and two matched controls per case were used in a nested case–control analysis. Shorter relative telomere length and higher methylation of LINE1 were associated with higher frequency of total chromosomal aberrations (β = ?0.76, P = 0.022; and β = 0.042, P = 0.048, respectively; age‐adjusted ordinal regression). The telomere length was stronger associated with chromosome‐type (β = ?1.00, P = 0.006) than with chromatid‐type aberrations (β = ?0.49, P = 0.115). The LINE1 methylation was stronger associated with chromatid‐type (β = 0.062, P = 0.003) than with chromosome‐type aberrations (β = 0.018, P = 0.41). Telomere length [individuals with short telomeres odds ratio (OR) = 0.87, 95% confidence interval (CI) 0.38–2.0], LINE1 (individuals with high methylation OR = 1.04, 95% CI 0.43–2.5) and chromosomal aberrations (individuals with high frequency OR = 1.6, 95% CI 0.63–3.9) at baseline did not predict cancer risk, but the conclusions were hampered by low statistical precision. The results suggest that shorter telomere length and higher LINE1 methylation in peripheral blood lymphocytes are predisposition factors for increased frequency of chromosomal aberrations. © 2012 Wiley Periodicals, Inc.     

Predicting blood pressure outcomes using single-item physician-administered measures: a retrospective pooled analysis of observational studies in Belgium

BackgroundPatient adherence is often not monitored because existing methods of evaluating adherence are either burdensome or do not accurately predict treatment outcomes.AimTo examine whether two simple, single-item physician-administered measures of patient adherence to antihypertensive medication are predictive of blood pressure outcomes.MethodUsing pooled data from five observational studies, a sample was identified of 9725 patients who were assessed using two single-item physician-administered measures of adherence to antihypertensive medication: the first item of the Basel Assessment of Adherence Scale (BAAS) and the Visual Analogue Scale (VAS). These two assessment tools were administered by GPs during regular appointments with patients. Systolic blood pressure (SBP), diastolic blood pressure (DBP), and combined SBP/DBP were measured at baseline and at 90 days.ResultsBAAS-identified adherent patients achieved lower mean SBP and DBP compared with non-adherent patients at 90 days (P<0.001), and had odds ratios of achieving blood pressure control of 0.66 (95% confidence intervals (CI) = 0.61 to 0.73, P<0.001) for SBP, 0.69 (95% CI = 0.62 to 0.76, P<0.001) for DBP, and 0.65 (95% CI = 0.59 to 0.72, P<0.001) for combined SBP/DBP. For VAS-identified adherent patients, the odds ratios of achieving blood pressure control were 0.93 (95% CI = 0.86 to 1.00, P<0.001) for SBP, 0.79 (95% CI = 0.73 to 0.85, P<0.001) for DBP, and 0.91 (95% CI = 0.84 to 0.99, P<0.001) for combined SBP/DBP.ConclusionsThe first item of the BAAS and the VAS are independent predictors of blood pressure control. These methods can be integrated seamlessly into routine clinical practice by allowing GPs to quickly evaluate a patient’s adherence and tailor treatment recommendations accordingly.     

Evaluation of a New Ambulatory Blood Pressure Monitor (Accutracker 102): Laboratory Comparisons With Direct Arterial Pressure, Stethoscopic Auscultatory Pressure, and Readings From a Similar Monitor (Spacelabs Model 5200)

Systolic (SBP) and diastolic (DBP) blood pressure levels generated by a new noninvasive ambulatory monitor, the Accutracker 102, were compared in the laboratory with intra-arterial pressure levels in 12 normotensive men, and with stethoscopic auscultatory determinations in 27 normotensive and hypertensive men and women over a wide range of within-subject pressure variations. In 11 subjects, its performance was also compared with another ambulatory monitor, the Spacelabs Model 5200. Highly positive correlations with both the intra-arterial (median r=+.90 for SBP, +.92 for DBP) and the stethoscopic standards (median r=+.93 for SBP, +.88 for DBP) were obtained using Accutracker's automatic readings (digital readout), while slightly higher correlations were obtained with hand-scoring of recorded data. The Spacelabs BP monitor also yielded readings that were highly correlated with stethoscopic readings (median r=+.83 for SBP, +.77 for DBP), although in 3 of the 11 subjects the Accutracker correlations were substantially higher than the Spacelabs correlations. Despite their generally good tracking of changes in pressure, both ambulatory monitors yielded absolute values in many subjects that differed by 5 mmHg or more from stethoscopic levels. The Accutracker's SBP levels were consistently too high and its DBP levels were occasionally too low, while Spacelabs' SBP and DBP values were too high and too low with equal frequency. However, mean deviation scores for each patient calculated from 5 concurrent ambulatory monitor and stethoscopic readings were shown to yield relatively stable correction factors for use when comparison with clinical standards is desired.     

Arterial pulse wave velocity and risk factors for peripheral vascular disease

Non-invasive measurement of arterial pulse wave velocity (PWV) is used to diagnose peripheral vascular disease. We examined the relationship between PWV and risk factors related to peripheral vascular disease [body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), serum total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C), atherogenic index (AI) and blood glucose (GLU)] in 45 healthy male volunteers, aged 25–85 years. The correlation coefficient of PWV with age was r=0.46, and the correlation coefficients of PWV with DBP, AI and GLU were r=0.71, 0.56, and 0.22, respectively (P < 0.05). Multiple linear regression analysis revealed that 67% of the variance in PWV could be accounted for by these three variables. The relative contributions of DBP, AI and GLU to PWV were 66%, 26% and 8%, respectively. To test the applicability of PWV for clinical use, a multiple regression equation of PWV derived from these three variables was then applied to male patients with hypertension (n=53), hyperlipidaemia (n=35) or hyperglycaemia (n=39). The results suggest that the multiple regression equation of PWV is an indicator that discriminates between these patient categories and healthy men. Accepted: 8 December 1999     

Bone status in elite male runners

The aim of our study was to compare long distance runners to body mass index (BMI)- and age-matched healthy controls with respect to bone parameters at all relevant loaded and nonloaded skeletal sites. Furthermore, we assessed the effect of running volume on bone parameters. Twenty elite male runners (21.1 km<1:15 h; volume >75 km/week/year) participated in the study (RG), 11 age- and BMI-matched male subjects (28±5 years) served as nontraining controls (CG). Subjects with any medication or illness affecting bone metabolism or with a family history of osteoporosis were not included. Bone parameters at various sites (total body, lumbar spine, femoral neck/hip, calcaneus) were measured by dual energy X-ray (DXA), quantitative computed tomography and quantitative ultrasound. Body composition was assessed via DXA and bioimpedance analysis; nutritional parameters were determined by 5-day dietary protocols. Training variables were assessed by questionnaires. Compared with nontraining controls runners had significantly higher BMD at all loaded sites (calcaneus, lower limbs, femoral neck, pelvis, and trabecular lumbar spine). BMD at nonloaded sites (ribs, upper limbs, and skull) was slightly but not significantly higher in the runners. We observed a low (r=0.30), nonsignificant association between training volume (km/week/year) and trabecular BMD of the femoral neck, which disappeared after adjusting for age, BMI, and body fat in this group of highly trained male runners. The effect of long distance running per se on bone parameters is not deleterious.     

Association of body composition and muscle function with hip geometry and BMD in premenopausal women

Abstract

Background: Muscle mass and function are related to bone mineral density (BMD) but associations with bone geometry and BMD at differently loaded hip regions are less well-known.

Aim: To examine associations of muscle strength, maximal impact forces and body composition with hip bone density and geometry.

Subjects and methods: In 88 sedentary, premenopausal women (32.6 ± 8.5 years), fat-free mass (FFM), isometric knee extension strength (IKES), and peak landing ground reaction force (GRF) were measured. BMD at the proximal femur and sub-regions, section modulus (Z), and cross-sectional area (CSA) were estimated using dual X-ray absorptiometry.

Results: BMD at hip sites was significantly associated with body mass, IKES, GRF and FFM (r = 0.31–0.50) whilst Z and CSA were correlated with FFM (r = 0.67 and 0.62, respectively). In multivariate models, variables explaining most variance were body mass for lower neck and shaft BMD (25% and 17%, respectively), IKES for upper neck BMD (21%), GRF for trochanter (19%) and total hip BMD (18%) and FFM for femoral neck Z, CSA and BMD (54%, 38% and 20%, respectively).

Conclusion: BMD at superolateral hip sites was most strongly related to muscle function and maximal impact forces, BMD at inferiomedial hip sites to body mass, and hip geometry to FFM.     

Growth-related disappearance of the childhood relationship between height and blood pressure levels

Context: Although there is a positive relationship between height and blood pressure (BP) levels in children, there are no reports regarding the association between height and BP levels in adolescents and adults.

Objective: This study examined whether there is an association between height and BP levels in Japanese adolescents.

Methods: The source population was all fifth (10 and 11-year-olds) and ninth graders (14 and 15-year-olds) who attended 11 elementary schools and five junior high schools in the Iwata area from 2002–2008. School-based screenings were conducted annually by the local government from April to June. Data obtained from health examinations were analysed, including anthropometric measurements and BP levels, for 11?780 children (98.7% of the source population).

Results: Height showed significant positive relationships with systolic blood pressure (SBP) and diastolic blood pressure (DBP) in childhood and in adolescent males. In contrast, the relationship between height and SBP was significantly weaker in adolescent females than in childhood and there was no significant relationship between height and DBP in adolescent females.

Conclusion: The relationship between height and SBP was attenuated by development in females and the relationship between height and DBP disappeared.     

The Relationship between Arterial Blood Pressure and Pulse Transit Time During Dynamic and Static Exercise

The relationships between arterial systolic and diastolic blood pressure (SBP and DBP), interbeat interval (IBI), and various pulse transit times were investigated in 5 young, healthy males during physical exercise and at rest. Transit times monitored were radial, brachial and dorsalis pedis RPIs (ECG R-wave to pulse intervals), and brachial-radial and radial-dorsalis pedis PPIs (pulse to pulse intervals). Experimental sessions consisted of three periods: two involving mild dynamic exercise plus rests, and one involving static exercise (handgrips) plus rests. Correlation and regression analyses within period and subject were performed on individual beat data. Radial RPI was highly correlated with SBP (during dynamic periods, range ?.57 to ?.89, median r?.81; during static periods, range ?.80 to ?.88, median r=?.87) and moderately correlated with DBP (during dynamic periods, range ?.10 to ?.63, median r?.52; during static periods, range ?.17 to ?.77, median r?.66). Median correlations of radial RPI with SBP and DBP during exercise and rest separately were ?.75 and ?.40 (dynamic), ?.79 and ?.57 (static), and ?.74 and ?.26 (rest). The IBI X radial RPI product was very highly correlated with the rate-pressure product (heart rate X SBP), an index of myocardial oxygen consumption (median r=?.96). The only PPI which reliably indexed SBP or DBP change was brachial-radial PPI during the static exercise period (median r=?.86 and ?.83).     

Blood pressure effects of long-term stimulant use in disorders of hypersomnolence

Untoward cardiovascular effects have been implicated as a deterrent to long-term central nervous system (CNS) stimulant use in disorders of hypersomnolence. In this study, we reviewed the relationship between blood pressure and long-term stimulant use. Medical records of 54 patients with narcolepsy and idiopathic CNS hyper- somnolence (ICH) were reviewed. The overall mean number of months of follow-up for the entire group was 45.6 (95% CI: 42–49). Both simple linear regression and multiple regression utilizing generalized estimating equations were used to show relationships between blood pressure (BP), time and other covariates. In the simple linear regression model, the average slope of the line of systolic BP (SBP) on time for the entire group was 0.06 (95% CI: -0.09, 0.13) and the line of diastolic BP (DBP) on time was 0.01 (95% CI: -0.05, 0.07). Two multiple regression equations were fitted for the continuous response variables SBP and DBP. Covariates in the model included: time, hypertension, weight at baseline, weight, SBP baseline (SBPBL), DBP baseline (DBPBL), high vs. low dose stimulant therapy and age at starting treatment. For SBP, the covariates weight at baseline, weight and SBPBL were significant (P< 0.05) predictors. For DBP, covariates reaching statistical significance (P< 0.05) included weight and DBPBL. There was no significant change in SBP or DBP over time in either model. Two different statistical models support the conclusion that there was no significant change in SBP or DBP over time in this population.     

Distance of walking in childhood and femoral bone density in perimenopausal women

Kuopio osteoporosis risk factor and prevention (OSTPRE) study is a population-based study from Eastern Finland. At baseline in 1989–91, bone densitometry of lumbar spine and femoral neck as assessed by DXA was carried out on women aged 48–58 (n = 3,222). In 1993, menarcheal age and health habits during adolescence were inquired from a postal inquiry. In 1996, a random sample of 254 women who had been premenopausal at baseline was interviewed over phone. They were asked how many kilometers per day they had walked to school and back, in each grade of primary school. The study sample (N = 185) was formed by excluding women with menarcheal age of >14 or <11 years. Women with any reported HRT history were also excluded. The mean age of the study sample was 50.7 (1.63) years, weight 70.8 (13.1) kg, height 161.5 (5.0) cm, and mean walking distance to and fro from the school at ages from 9 to 11 years was 2.7 (1.7) km. In regression analysis, the walking distance was associated with femoral BMD (r = 0.18, P = 0.015). After adjusting for baseline age, weight and height, this association persisted (P = 0.025). When walking distance was categorized as I = 0–0.549 km, II = 0.55–1.99 km, III = 2.0–4.99 and IV = 5.0 km and more, the respective means for femoral BMDs were 0.92, 0.97, 0.98 and 1.01 g/cm². Statistical significance persisted after adjusting for height, weight, age, grip strength, calcium intake, smoking, place of residence, use of contraceptive pills, physical load of work and baseline physical activity (P = 0.032). A 10 year follow-up revealed no changes in bone loss rate between the groups and femoral BMD benefits persisted (repeated measures analysis = NS). Walking distance was not associated with spinal bone density. Even though walking is a low impact activity, walking before menarche may have a moderate but long-lasting positive effect on femoral peak bone density. Lack of walking and similar low impact physical activities during peak growth years may have a negative effect on peak bone mass formation.     

Association between time spent in sedentary,moderate to vigorous physical activity,body mass index,cardiorespiratory fitness and blood pressure

Background: Elevated blood pressure (BP) has been reported in young people and seems to be associated with body mass index (BMI) and reduced physical activity (PA).

Aim: This study sought to analyse the association of BP with BMI, PA intensity patterns and cardiorespiratory fitness (CRF) in youth.

Subjects and methods: A cross-sectional study was carried out including 66 boys (13.91±1.76) and 97 girls (14.02±1.71). Anthropometric characteristics, CRF and BP were assessed during school time and accelerometers were utilized to determine intensity of PA.

Results: The linear regression model, adjusted for age, sex and height, showed that higher values of BMI were associated (p≤0.05) with higher values of systolic blood pressure (SBP) (1.39; 95% CI: 0.56; 2.23) and diastolic blood pressure (DBP) (1.52; 95% CI: 0.68; 2.37). Additionally, SBP, but not DBP, was inversely associated (p≤0.05) with moderate PA (?0.25; 95% CI: ?0.47; ?0.02) and positively correlated with sedentary activities (0.04; 95% CI: 0.00; 0.08).

Conclusion: The present study showed that BMI and time spent in sedentary activities were inversely associated with SBP. However, time spent in moderate PA was positively associated with SBP. BMI was the single predictor of DBP.     

Increased systolic blood pressure after mild cold and rewarming: relation to cold-induced thermogenesis and age

Aim: Higher winter mortality in elderly has been associated with augmented systolic blood pressure (SBP) response and with impaired defense of core temperature. Here we investigated whether the augmented SBP upon mild cold exposure remains after a rewarming period, and whether SBP changes are linked to thermoregulation. Therefore, we tested the following hypotheses: cold‐induced increase in SBP (1) remains augmented after rewarming in elderly compared to young adults (2) is related to non‐shivering thermogenesis (NST) upon mild cold (3) is related to vasoconstriction upon mild cold. Methods: Blood pressure, energy expenditure (EE), skin and core temperature, skin perfusion (abdomen, forearm, both sides of hand) and % body fat were measured in 12 young adults (Y) and 12 elderly (E). Supine subjects were exposed to a thermoneutral baseline 0.5 h (T_air = 30.1 °C), 1 h mild cold (T_air = 20.7 °C), 1 h rewarming (T_air = 34.8 °C) and 1 h baseline (T_air = 30.5 °C). Results: Upon mild cold only the young adults showed significant NST (Y: +2.5 ± 0.6 W m^?2, P < 0.05). No significant age effects in vasoconstriction were observed. After rewarming per cent change in SBP (%ΔSBP) remained significantly increased in both age groups and was augmented in elderly (Y: +5.0% ± 1.2% vs. E: +14.7% ± 3.1%, P < 0.05). Regression analysis revealed that %ΔSBP significantly related to ΔEE upon mild cold (P < 0.01, r² = 0.35) and in elderly also to %body fat (P < 0.02, r² = 0.57). Conclusion: Individual changes in SBP after rewarming correlate negatively to NST. Elderly did not show NST, which explains the greater SBP increase in this group. In elderly a relatively large %body fat protected against the adverse effects of mild cold.     

Physical activity, cardio-respiratory fitness, and metabolic traits in rural Mexican Tarahumara

Objectives: To study the association between physical activity energy expenditure (PAEE) and cardio‐respiratory fitness (CRF) with key metabolic traits and anthropometric measures in the Tarahumara of Mexico. Methods: A cross‐sectional study was carried out in five rural communities in Chihuahua, México including 64 adult Tarahumara, mean (SD) age 40.7 (12.9) years. Using a combined accelerometer and heart rate sensor, PAEE was measured over three consecutive days and nights and a sub‐maximal step test was carried out in order to (1) calibrate heart rate at the individual level and (2) to estimate CRF. Random blood glucose level and resting blood pressure (BP) were measured with standard anthropometrics. Results: Mean (SD) PAEE was 71.2 (30.3) kJ kg^?1 day^?1 and CRF was 36.6 (6.5) mlO₂ min^?1 kg^?1. Mean (SD) glucose was 127.9 (32.4) mg/dl, with 3.3% having diabetes. Mean (SD) systolic and diastolic BP was 122 (20.8) and 82 (14.8) mm Hg, respectively, with 28.1% having hypertension. Mean body mass index was 27.5 (4.2) kg m^?2, with 71.9% being overweight. Following adjustment for age and sex, weak inverse associations were observed between PAEE and systolic BP (β = ?0.20, P = 0.27) and diastolic BP (β = ?0.16, P = 0.23); and between CRF and systolic BP (β = ?0.51, P = 0.14) and diastolic BP (β = ?0.53, P = 0.06). The inverse associations with glucose were also weak and not statistically significant for neither PAEE (β = ?0.01, P = 0.63) nor CRF (β = ?0.05, P = 0.27). Conclusions: This study suggests high levels of overweight and hypertension in the Tarahumara, and points to fitness and physical activity as potential intervention targets although findings should be confirmed in larger samples. Am. J. Hum. Biol. 2012. © 2012 Wiley Periodicals, Inc.     

The effects of body mass index and age on cross‐sectional properties of the femoral neck

Research on the relationship between body mass index (BMI) and cross‐sectional geometry of long bone diaphyses demonstrates that strength properties are significantly greater in obese versus normal BMI individuals. However, articular dimensions do not differ appreciably. If femoral head size remains constant, we hypothesize that the femoral neck remodels to accommodate greater loads associated with increased BMI. High‐resolution CT scans (n = 170 males) were divided into three BMI groups (normal, overweight, and obese) and two age groups (21–50 and >50). OsiriX software was used to obtain a cross‐sectional slice at the waist of the femoral neck. Cortical area (CA), total cross‐sectional area (TA), percent cortical area (%CA), circularity index (I_max/I_min), section modulus (Z_pol), and second moment of area (J) were measured with ImageJ software. The effects of age and BMI were evaluated statistically. Pairwise comparisons in the younger group only detected significant differences between normal and obese males in the circularity index (P = 0.022). The older cohort showed significant differences in CA (P < 0.001), %CA (P = 0.004), Z_pol (P = 0.007), and J (P < 0.001) between normal and obese groups. This study shows that the effects of obesity on the cross‐sectional geometry of the femoral neck are more pronounced in older males relative to younger males. Older males with increased BMI have greater cortical area and bone strength in the femoral neck relative to younger males, thus making the femoral neck less susceptible to fractures in obese individuals. Clin. Anat. 28:1048–1057, 2015. © 2015 Wiley Periodicals, Inc.     

Percentiles of waist–hip ratio and the relationship with blood pressure among children and adolescents in Shandong,China

Background: Anthropometric indices such as waist circumference (WC), waist-to-height ratio (WHtR) and waist–hip ratio (WHR) have been recognized as useful alternatives to visceral fat measurement in epidemiological studies. WHR has been used extensively in adults. However, there are very few published data for WHR among children and adolescents.

Aim: The present study examined the distribution of WHR and the relationship with blood pressure (BP) among children and adolescents in Shandong, PR China.

Subjects and methods: Data for this study were obtained from a large cross-sectional survey of schoolchildren carried out in 2010. A total of 38?822 students (19?456 boys and 19?366 girls) aged 7–17 years participated in this study. WC, Hip circumference (HC), systolic blood pressure (SBP) and diastolic blood pressure (DBP) of all subjects were measured; WHR was calculated as WC divided by HC. Abdominal obesity was defined by previously published WHR references based on Chinese children and adolescents living in Beijing. All subjects were divided into two groups (group 1 with WHR <85th; group 2 with WHR ≥85th) according to the percentiles of WHR and comparisons of the SBP and DBP between the two groups were made.

Results: The WHR levels in Shandong boys and girls were lower than those from German and Pakistani. The overall prevalence of abdominal obesity was 9.53% (95% CI?=?9.12–9.95%) for boys and 9.82% (95% CI?=?9.40–10.24%) for girls, no statistical differences between the two genders were observed (p?>?0.05). In both boys and girls, the Z-scores of SBP and DBP were all significantly lower in group 1 than in group 2 (p?Conclusion: WHR is useful in identifying children and adolescents at risk of developing high BP. These findings, together with the known tracking of BP from adolescence into adulthood, highlight the importance of preventing overweight and obesity among children and adolescents in order to prevent the development of hypertension in adults.     

Blood pressure and pain sensitivity in children and adolescents

Elevated blood pressure is associated with diminished pain sensitivity. While this finding is well established in adults, it is less clear when the relation between blood pressure and pain sensitivity emerges across the life course. Evidence suggests this phenomenon may exist during childhood. Children (N = 309; 56% boys) aged 10–15 years and their parents participated. Blood pressure readings were taken during a resting baseline. Maximum pain intensity was rated using a visual analogue scale (rated 0–10) in response to a finger prick pain induction. Parent‐measured resting blood pressure was inversely associated with boys' pain ratings only. Cross‐sectionally, lower pain ratings were related to higher SBP, univariately. Longitudinally, pain ratings predicted higher DBP, even after controlling for covariates. Determining when and how the relation between blood pressure and pain sensitivity emerges may elucidate the pathophysiology of hypertension.