Skeletal muscle fibre type and enzymatic activity in adult offspring following placental and peripheral malaria exposure in foetal life.

Background: Maternal malaria may restrict foetal growth. Impaired utero-placental blood flow due to malaria infection may cause hypoxia-induced altered skeletal muscle fibre type distribution in the offspring, which may contribute to insulin resistance and impaired glucose metabolism. This study assessed muscle fibre distribution 20 years after placental and/or peripheral in-utero malaria exposure compared to no exposure, i.e., PPM+, PM+, and M-, respectively. Methods: We traced 101 men and women offspring of mothers who participated in a malaria chemosuppression study in Muheza, Tanzania. Of 76 eligible participants, 50 individuals (29 men and 21 women) had skeletal muscle biopsy taken from m. vastus lateralis in the right leg. As previously reported, fasting and 30 min post-oral glucose challenge plasma glucose values were higher, and insulin secretion disposition index was lower, in the PPM+ group. Aerobic capacity (fitness) was estimated by an indirect VO2max test on a stationary bicycle. Muscle fibre sub-type (myosin heavy chain, MHC) distribution was analysed, as were muscle enzyme activities (citrate synthase (CS), 3-hydroxyacyl-CoA dehydrogenase, myophosphorylase, phosphofructokinase, lactate dehydrogenase, and creatine kinase activities. Between-group analyses were adjusted for MHC-I %. Results: No differences in aerobic capacity were found between groups. Despite subtle elevations of plasma glucose levels in the PPM+ group, there was no difference in MHC sub-types or muscle enzymatic activities between the malaria-exposed and non-exposed groups. Conclusion: The current study did not show differences in MHC towards glycolytic sub-types or enzymatic activity across the sub-groups. The results support the notion of the mild elevations of plasma glucose levels in people exposed to placental malaria in pregnancy being due to compromised pancreatic insulin secretion rather than insulin resistance.

Pre-pregnancy body mass index and gestational weight-gain predict maternal hemoglobin levels and are jointly associated with neonatal outcomes in a Mexican birth cohort.

Introduction: Introduction: there is scarce evidence of the effects of obesity and gestational weight- gain (GWG) on hemoglobin (Hb) levels in pregnancy. Little is known about the implications in offspring when pregnant mothers present with both at delivery. Aim: to identify if pre-pregnancy body mass index (BMI) and GWG are associated with Hb levels at pregnancy third trimester; and identify if the BMI status plus anemia at delivery could influence offspring anthropometry. Methods: in a sub-sample of pregnant women (n = 108) and their offspring (n = 63) from a Mexican birth cohort, information from medical files and questionnaires were used to obtain pre-pregnancy BMI (categorized as normal, overweight, and obese), GWG, and Hb during pregnancy; at delivery and postpartum anthropometric measures were obtained for offspring. Adjusted regression models predicted Hb levels according to pre-pregnancy BMI and GWG; offspring growth trajectories from birth to 3 months old were compared according to mother´s BMI status and anemia combinations at delivery. Results: pre-pregnancy normal (N), overweight (OV), and obesity (OB) were present in 48 %, 40 %, and 12 % of the participants, respectively. Anemia was detected in 22.8 % of the participants at third trimester. Hb levels in the third trimester were significantly lower in those with pre-pregnancy OB-BMI and excessive GWG (12.1 g/dL, 95 % CI: 10.7-13.5) compared to those with pre-pregnancy OB-BMI and insufficient GWG (13.3g/dL, 95 %CI: 11.9-14.8) (p = 0.04). At delivery, 11 % presented with OB-BMI and anemia. Women with OB-BMI and normal Hb levels had children with higher scores in Weight-for-Length-Z score and triceps skinfold. Conclusion: among OB women, excessive GWG was associated with having lower Hb levels in the third trimester. Newborns had higher scores in growth patterns related to adiposity from birth to 3 months old if mothers had normal Hb levels and OB.

Introducción: Introducción: existe escasa evidencia de los efectos de obesidad y ganancia de peso gestacional (GPG) y niveles de hemoglobina (Hb) durante el embarazo. Poco se conoce sobre las implicaciones en la descendencia cuando las embarazadas presentan ambos en el momento del parto. Objetivos: identificar si el índice de masa corporal (IMC) previo al embarazo y el GPG están asociados con los niveles de Hb en el tercer trimestre del embarazo; e identificar si el IMC más la anemia en el momento del parto podrían influir en la antropometría de la descendencia. Metodología: se utilizó información de expedientes médicos y cuestionarios para obtener el IMC antes del embarazo (categorizado como normal, con sobrepeso y obesidad), GPG y Hb durante el embarazo; en el momento del parto y posparto se obtuvieron medidas antropométricas para la descendencia de una submuestra de mujeres embarazadas (n = 108) y su descendencia (n = 63) de una cohorte mexicana. Los modelos de regresión ajustados predijeron los niveles de Hb según IMC y GPG antes del embarazo; se compararon las trayectorias de crecimiento de la descendencia desde el nacimiento hasta los 3 meses de edad según el estado de IMC de la madre y las combinaciones de anemia en el momento del parto. Resultados: peso preembarazo normal (N), sobrepeso (SP) y obesidad (OB) estuvieron presentes en 48 %, 40 % y 12 % de las participantes, respectivamente. Se diagnosticó anemia en el 22,8 % de las participantes en el tercer trimestre. Los niveles de Hb en el tercer trimestre fueron significativamente más bajos en aquellas con IMC-OB antes del embarazo y GPG excesivo (12,1 g/dL, IC del 95 %: 10,7-13,5) en comparación con aquellas con IMC-OB antes del embarazo y GPG insuficiente (13,3 g/dl, IC del 95 %: 11,9-14,8) (p = 0,04). Al momento del parto, el 11 % presentó OB-BMI y anemia. Las mujeres con OB-BMI y niveles normales de Hb tenían hijos con puntuaciones más altas en puntuación Z de peso para longitud y pliegue cutáneo del tríceps. Conclusión: la GPG excesiva entre las mujeres OB se asoció con niveles más bajos de Hb en el tercer trimestre. Los recién nacidos tenían puntajes más altos en los patrones de crecimiento relacionados con la adiposidad desde el nacimiento hasta los 3 meses de edad si las madres tenían niveles normales de Hb y OB.

Cardiorespiratory fitness assessment using risk-stratified exercise testing and dose-response relationships with disease outcomes.

Cardiorespiratory fitness (CRF) is associated with mortality and cardiovascular disease, but assessing CRF in the population is challenging. Here we develop and validate a novel framework to estimate CRF (as maximal oxygen consumption, VO2max) from heart rate response to low-risk personalised exercise tests. We apply the method to examine associations between CRF and health outcomes in the UK Biobank study, one of the world's largest and most inclusive studies of CRF, showing that risk of all-cause mortality is 8% lower (95%CI 5-11%, 2670 deaths among 79,981 participants) and cardiovascular mortality is 9% lower (95%CI 4-14%, 854 deaths) per 1-metabolic equivalent difference in CRF. Associations obtained with the novel validated CRF estimation method are stronger than those obtained using previous methodology, suggesting previous methods may have underestimated the importance of fitness for human health.

Antioxidant biomarkers and cardiometabolic risk markers in an Aboriginal community in remote Australia: a cross-sectional study.

OBJECTIVE: High-quality diets, characterised by nutrient-rich foods, are one of the foundations for health and well-being. Indicators of diet quality, antioxidants, are associated with protection against cardiometabolic diseases. The current study explores relationships between plasma antioxidants and cardiometabolic risk among Aboriginal people in Australia. DESIGN: As part of a community-driven health promotion programme, we conducted a cross-sectional study including a health-behaviour questionnaire, plasma antioxidants and cardiometabolic risk markers (anthropometric, blood pressure measurements, fasting glucose, glycated Hb (HbA1c), lipids, C-reactive protein and albumin-creatinine-ratio) continuous and categorised into population-specific cut-offs. Antioxidants (ß-carotene, ß-cryptoxanthin, lycopene, lutein-zeaxanthin, retinol and α-tocopherol measured using HPLC) were applied to a principal component analysis, which aggregated these into a single component. Linear regression models were applied to investigate associations between the antioxidant component and cardiometabolic risk markers. SETTING: Community in a remote area in Northern Territory, Australia. PARTICIPANTS: A total of 324 Aboriginal people, mean age 35·5 (range 15-75) years. RESULTS: Antioxidant component levels were higher among individuals with higher self-reported vegetable intake (P < 0·01), higher among individuals with higher self-reported fruit intake (P = 0·05) and lower among current smokers (P = 0·06). Linear regression revealed an inverse association between the antioxidant component and C-reactive protein (ß = -0·01, P < 0·01) after adjusting for confounders. CONCLUSION: Higher plasma antioxidant levels, indicators of diet quality, were associated with lower levels of high-sensitivity C-reactive protein in this Aboriginal population in remote Australia. This association suggests plasma antioxidants may be protective against inflammation; however, longitudinal studies are needed to examine this potentially protective relationship.

Hemoglobin levels and blood pressure are associated in rural black africans.

OBJECTIVES: The association between blood levels of hemoglobin (B-hgb) and blood pressure (BP) has been widely investigated in Caucasians and Asians but there is a paucity of data in rural black Africans. The objective was to investigate the association between B-hgb and BP in a rural black African population. METHODS: A cross-sectional study was conducted in three districts in Kenya (Bondo, Kitui, and Transmara) with the inclusion of participants aged ≥17 years. Background information, anthropometry, BP, B-hgb, hepatic insulin resistance (HOMA2-IR), standard lipid profile, and oral glucose tolerance test were obtained in each participant. RESULTS: Background characteristics among 1,167 participants showed that anemic and non-anemic participants differed significantly from each other as there were more women, lower body mass index and waist circumference (WC), lower degree of hepatic insulin resistance and plasma cholesterols among the anemic participants. Furthermore, anemic participants had significantly lower systolic and diastolic BP (P < 0.01) but not a significantly different prevalence of hypertension (P = 0.08). Multivariate linear regression models adjusted for-age, sex, plasma total-cholesterol, WC, Log2(HOMA2-IR), ethnicity, and smoking status-revealed that B-hgb (per mmol/l increment) was significantly associated with systolic BP (estimate: 1.18 (0.37-1.98)) and diastolic BP (estimate: 1.06 (0.54-1.57)) (P < 0.01). CONCLUSIONS: B-hgb is associated with BP in rural black Africans.

HbA1c, fasting and 2 h plasma glucose in current, ex- and never-smokers: a meta-analysis.

AIMS/HYPOTHESIS: The relationships between smoking and glycaemic variables have not been well explored. We compared HbA1c, fasting plasma glucose (FPG) and 2 h plasma glucose (2H-PG) in current, ex- and never-smokers. METHODS: This meta-analysis used individual data from 16,886 men and 18,539 women without known diabetes in 12 DETECT-2 consortium studies and in the French Data from an Epidemiological Study on the Insulin Resistance Syndrome (DESIR) and Telecom studies. Means of three glycaemic variables in current, ex- and never-smokers were modelled by linear regression, with study as a random factor. The I (2) statistic was used to evaluate heterogeneity among studies. RESULTS: HbA1c was 0.10% (95% CI 0.08, 0.12) (1.1 mmol/mol [0.9, 1.3]) higher in current smokers and 0.03% (0.01, 0.05) (0.3 mmol/mol [0.1, 0.5]) higher in ex-smokers, compared with never-smokers. For FPG, there was no significant difference between current and never-smokers (-0.004 mmol/l [-0.03, 0.02]) but FPG was higher in ex-smokers (0.12 mmol/l [0.09, 0.14]). In comparison with never-smokers, 2H-PG was lower (-0.44 mmol/l [-0.52, -0.37]) in current smokers, with no difference for ex-smokers (0.02 mmol/l [-0.06, 0.09]). There was a large and unexplained heterogeneity among studies, with I (2) always above 50%; I (2) was little changed after stratification by sex and adjustment for age and BMI. In this study population, current smokers had a prevalence of diabetes that was 1.30% higher as screened by HbA1c and 0.52% lower as screened by 2H-PG, in comparison with never-smokers. CONCLUSION/INTERPRETATION: Across this heterogeneous group of studies, current smokers had a higher HbA1c and lower 2H-PG than never-smokers. This will affect the chances of smokers being diagnosed with diabetes.

Skiing across the Greenland icecap: divergent effects on limb muscle adaptations and substrate oxidation.

This study investigates the adaptive response of the lower limb muscles and substrate oxidation during submaximal arm or leg exercise after a crossing of the Greenland icecap on cross-country skies. Before and after the 42-day expedition, four male subjects performed cycle ergometer and arm-cranking exercise on two separate days. On each occasion, the subjects exercised at two submaximal loads (arm exercise, 45 W and 100 W; leg exercise, 100 W and 200 W). In addition, peak oxygen uptake ((VO(2max))) was determined for both leg and arm exercise. Before and after the crossing, a muscle biopsy was obtained from the vastus lateralis and the triceps brachii muscles prior to exercise (N=3). After the crossing, body mass decreased by 5.7+/-0.5 kg (in four of four subjects), whereas (VO(2max)) was unchanged in the arm (3.1+/-0.2 l min(-1)) and leg (4.0+/-0.1 l min(-1)). Before the crossing, respiratory exchange ratio (RER) values were 0.84+/-0.02 and 0.96+/-0.02 during submaximal arm exercise and 0.82+/-0.02 and 0.91+/-0.01 during submaximal leg exercise at the low and high workloads, respectively. After the crossing, RER was lower (in three of four subjects) during arm exercise (0.74+/-0.02 and 0.81+/-0.01) but was higher (in three of four subjects) during leg exercise (0.92+/-0.02 and 0.96+/-0.01) at the low and high workloads, respectively. Citrate synthase and beta-hydroxy-acyl-CoA-dehydrogenase activity was decreased by approximately 29% in vastus lateralis muscle and was unchanged in triceps brachii muscle. Fat oxidation during submaximal arm exercise was enhanced without a concomitant increase in the oxidative capacity of the triceps brachii muscle after the crossing. This contrasted with decreased fat oxidation during leg exercise, which occurred parallel to a decreased oxidative capacity in vastus lateralis muscle. Although the number of subjects is limited, these results imply that the adaptation pattern after long-term, prolonged, low-intensity, whole body exercise may vary dramatically among muscles.