Antibodies to Helminth Defense Molecule-1 are associated with inflammation, organomegaly, and decreased nutritional status in schistosomiasis japonica.

Immunomodulation enhances parasite fitness by reducing inflammation-induced morbidity in the mammalian host, as well as by attenuating parasite-targeting immune responses. Using a whole proteome differential screening method, we identified Schistosoma japonicum Helminth Defense Molecule (SjHDM-1) as a target of antibodies expressed by S. japonicum resistant, but not susceptible, individuals. In a longitudinal cohort study (N=644) conducted in a S. japonicum endemic region of the Philippines, antibody levels to SjHDM-1 did not predict resistance to reinfection but were associated with increased measures of inflammation. Individuals with high levels of anti-SjHDM-1 IgG had higher levels of C-reactive protein compared to individuals with low anti-SjHDM-1. High anti-SjHDM-1 IgG responses were also associated with reduced biomarkers of nutritional status (albumin), as well as decreased anthropometric measures of nutritional status (WAZ and HAZ) and increased measures of hepatomegaly. Our results suggest that anti-SjHDM-1 responses inhibit the immunomodulatory function of SjHDM-1, resulting in increased morbidity.

Dietary patterns and their socio-demographic correlates in the context of migration and urbanisation demonstrate nutrition transitions in South Africa.

This paper investigates the demographic and socio-economic correlates of dietary patterns in South Africa, drawing on a sample of young adults experiencing internal migration and urbanisation. We use data from the 2018 baseline survey of the Migrant Health Follow-Up Study, an original longitudinal cohort study consisting of 3,087 internal migrants and rural residents aged 18-40 nested within the Agincourt Health and socio-Demographic Surveillance System in rural northeast South Africa. We employ principal components analysis to identify dietary patterns from food frequency questionnaires and ordinary least squares regression to assess whether migration and other socio-economic characteristics correlate with specific dietary patterns at baseline. We observe five distinct dietary patterns characterised by frequent consumption of processed foods, red meat, fruits and vegetables, diverse foods, and high sugar/fat foods. We find migration to be significantly associated with more frequent consumption of both processed foods and fruits and vegetables; we also find the association between migration status and dietary patterns to be heterogenous depending on migrants' destinations. This paper extends current understanding of changing dietary patterns in the context of nutrition transitions with attention to dynamic migration processes rather than static rural-urban differences.

Cardiometabolic Health in Pregnancy and Postpartum: Findings From a Prospective Cohort Study in South Africa.

Background: The cardiometabolic impact of HIV infection and treatment with antiretroviral therapy (ART) in pregnancy and the postpartum period remains unclear. Methods: We enrolled pregnant persons with (PHIV) and without HIV in Cape Town, South Africa, who were ≥18 years old at 24-28 weeks' gestation and followed them up to 32 months postpartum. We estimated associations between HIV status and cardiometabolic risk including body mass index (BMI), obesity (BMI ≥30 kg/m2), blood pressure (BP; elevated systolic BP ≥130 and/or diastolic ≥85 mmHg), lipid levels, and metabolic syndrome according to the Joint Interim Statement criteria using multivariable log binomial or linear regression models. Subgroup analyses compared PHIV on efavirenz (EFV)- vs dolutegravir (DTG)-based ART. Results: Among 400 participants (n = 200 without HIV, n = 200 PHIV), 52% had prepregnancy obesity and 9% had elevated BP. Postpartum, 57% were classified with obesity, 31% had elevated BP, and 29% had metabolic syndrome. In multivariable analyses, HIV was associated with a lower BMI prepregnancy but not postpartum; however, mean indices were in the obese range regardless of HIV status. Neither BMI nor obesity prepregnancy or postpartum differed by ART regimen. Among PHIV, participants on DTG had higher levels of elevated BP in pregnancy and postpartum, compared with PHIV on EFV. Conclusions: We observed high levels of obesity, elevated BP, and metabolic syndrome in the perinatal period but few differences by HIV status. Participants on DTG may be more likely to have elevated BP in pregnancy and postpartum. Monitoring of cardiometabolic health for pregnant persons on DTG is warranted.

Associations between fasting glucose rate-of-change and the missense variant, rs373863828, in an adult Samoan cohort.

BACKGROUND: The A allele of rs373863828 in CREB3 regulatory factor is associated with high Body Mass Index, but lower odds of type 2 diabetes. These associations have been replicated elsewhere, but to date all studies have been cross-sectional. Our aims were (1) to describe the development of type 2 diabetes and change in fasting glucose between 2010 and 2018 among a longitudinal cohort of adult Samoans without type 2 diabetes or who were not using diabetes medications at baseline, and (2) to examine associations between fasting glucose rate-of-change (mmol/L per year) and the A allele of rs373863828. METHODS: We describe and test differences in fasting glucose, the development of type 2 diabetes, body mass index, age, smoking status, physical activity, urbanicity of residence, and household asset scores between 2010 and 2018 among a cohort of n = 401 adult Samoans, selected to have a ~2:2:1 ratio of GG:AG: AA rs373863828 genotypes. Multivariate linear regression was used to test whether fasting glucose rate-of-change was associated with rs373863828 genotype, and other baseline variables. RESULTS: By 2018, fasting glucose and BMI significantly increased among all genotype groups, and a substantial portion of the sample developed type 2 diabetes mellitus. The A allele was associated with a lower fasting glucose rate-of-change (ß = -0.05 mmol/L/year per allele, p = 0.058 among women; ß = -0.004 mmol/L/year per allele, p = 0.863 among men), after accounting for baseline variables. Mean fasting glucose and mean BMI increased over an eight-year period and a substantial number of individuals developed type 2 diabetes by 2018. However, fasting glucose rate-of-change, and type 2 diabetes development was lower among females with AG and AA genotypes. CONCLUSIONS: Further research is needed to understand the effect of the A allele on fasting glucose and type 2 diabetes development. Based on our observations that other risk factors increased over time, we advocate for the continued promotion for diabetes prevention and treatment programming, and the reduction of modifiable risk factors, in this setting.

Associations of childhood BMI traits with blood pressure and glycated haemoglobin in 6-9-year-old Samoan children.

INTRODUCTION: Prevalence and risk factors for elevated glycated haemoglobin (HbA1c) and blood pressure (BP) are poorly understood among Pacific children. We examined associations of HbA1c and BP in 6-9 year-olds with body mass index (BMI) at ages 2, 5, and BMI velocity between 2-9 years in Samoa. METHODS: HbA1c (capillary blood) and BP were measured in n = 410 Samoan children who were part of an ongoing cohort study. Multilevel models predicted BMI trajectory characteristics. Generalized linear regressions assessed associations of childhood characteristics and BMI trajectories with HbA1c and BP treated as both continuous and categorical outcomes. Primary caregiver-reported childhood characteristics were used as covariates. RESULTS: Overall, 12.90% (n = 53) of children had high HbA1c (≥5.7%) and 33.17% (n = 136) had elevated BP. BMI at 5-years and BMI velocity were positively associated with high HbA1c prevalence in males. A 1 kg/m2 per year higher velocity was associated with a 1.71 (95% CI: 1.07, 2.75) times higher prevalence of high HbA1c. In females, higher BMI at 5-years and greater BMI velocity were associated with higher BP at 6-9 years (95% CI: 1.12, 1.40, and 1.42, 2.74, respectively). CONCLUSION: Monitoring childhood BMI trajectories may inform cardiometabolic disease screening and prevention efforts in this at-risk population.

Gestational weight gain and adverse birth outcomes in South African women with HIV on antiretroviral therapy and without HIV: a prospective cohort study.

INTRODUCTION: Outside of pregnancy, evidence shows that persons with HIV initiating or switching to dolutegravir (DTG)-based antiretroviral therapy (ART) experience greater weight gain compared to those on other ART classes. However, there are few data on the impact of DTG-based ART on gestational weight gain (GWG) in sub-Saharan Africa where HIV is most common. According to the National Academy of Medicine (NAM), GWG below and above NAM guidelines is associated with adverse birth outcomes. Therefore, the objective of this study was to describe GWG by HIV status and ART regimen, and examine the associations with adverse birth outcomes. METHODS: We enrolled pregnant women with HIV (WHIV) and without HIV (≥18 years) in a peri-urban primary healthcare facility in Cape Town, South Africa between 2019 and 2022. GWG was study-measured at 24-28 (baseline) and 33-38 weeks gestation and converted to GWG rate (kg/week) in accordance with NAM guidelines. GWG z-scores were generated using the INTEGROWTH-21 and US standards to account for differing lengths of gestation. Birth outcome data were obtained from medical records. Associations of GWG z-score with adverse birth outcomes were assessed using multivariable linear or log-binomial regression. RESULTS: Among 292 participants (48% WHIV), median age was 29 years (IQR, 25-33), median pre-pregnancy body mass index (BMI) was 31 kg/m2 (IQR, 26-36) and 20% were primiparous at baseline. The median weekly rate of GWG was 0.30 kg/week (IQR, 0.12-0.50), 35% had GWG below NAM standards (59% WHIV) and 48% had GWG above NAM standards (36% WHIV). WHIV gained weight more slowly (0.25 vs. 0.37 kg/week, p<0.01) than women without HIV. Weekly rate of GWG did not differ by ART regimen (DTG-based ART 0.25 vs. efavirenz-based ART 0.27 kg/week, p = 0.80). In multivariable analyses, GWG z-score was positively associated with continuous birth weight (mean difference = 68.53 95% CI 8.96, 128.10) and categorical high birth weight of >4000 g (RR = 2.18 95% CI 1.18, 4.01). CONCLUSIONS: Despite slower GWG among WHIV, nearly half of all women gained weight faster than recommended by the NAM. GWG was positively associated with infant birth weight. Interventions to support healthy GWG in sub-Saharan Africa are urgently needed.

Child, family and household characteristics associated with physical activity in Samoan children aged 3-8 years: A cross-sectional study.

Physical activity is a key component of many obesity prevention strategies. The aim of this analysis was to identify child, family, and household characteristics associated with parent-reported physical activity in Samoan children aged 3-8 years. Children (n = 445; 51.2% female, mean age 5.4 years) were part of an ongoing, mixed-longitudinal study of child growth, development, and wellbeing (the Ola Tuputupua'e cohort). Bivariate analyses and multivariate generalized linear regressions were conducted to investigate the relationship of child, family, and household characteristics with physical activity level, measured using the Netherlands Physical Activity Questionnaire (NPAQ). Children were classified as being 'highly active' if they had NPAQ scores in the 75th percentile or above. Among the n = 111 children classified as 'highly active', n = 67 (60.4%) were boys. After adjusting for child, family, and household-level characteristics, hours of child sleep per night was the only variable significantly associated with odds of being highly active. Compared to children who slept less than 9 hours at night, those who slept 10-10.99 hours (OR: 5.97, 95% CI: 2.14-18.13) and 11+ hours (OR: 25.75, 95% CI: 8.14-90.12) had higher odds of being 'highly active'. Future research should examine the mechanisms driving the relationship between nighttime sleep and physical activity among Samoan children. Intervening on sleep duration and quality may improve physical activity and, in turn, obesity risk in this setting.

Accelerometer-Based Estimates of Physical Activity and Sedentary Time Among Samoan Adults.

BACKGROUND: The prevalence of obesity-related cardiometabolic disease in Samoa is among the highest globally. While physical activity is a modifiable risk factor for obesity-related disease, little is known about physical activity levels among adult Samoans. Using wrist-worn accelerometer-based devices, this study aimed to characterize physical activity among Samoan adults. METHODS: Samoan adults (n = 385; 55% female, mean [SD] age 52 [10] y) wore Actigraph GT3X+ devices for 7 to 10 days. General linear models were used to examine mean daily minutes of sedentary time, light physical activity, and moderate to vigorous physical activity by various participant characteristics. RESULTS: Time spent in moderate to vigorous physical activity did not differ statistically between men (88 [5] min; 95% confidence interval [CI], 80-97) and women (78 [4] min; 95% CI, 70-86; P = .08). Women, however, spent more time than men in light physical activity: 380 (7) minutes (95% CI, 367-393) versus 344 (7) minutes (95% CI, 329-358; P < .001). While there were no differences in physical activity by census region, education, or occupation among women, men in urban areas spent significantly less time in moderate to vigorous physical activity than those in peri-urban and rural areas (P = .015). Women with class II/III obesity spent more time in sedentary activities than those with healthy weight or overweight/class I obesity (P = .048). CONCLUSIONS: This study characterizes physical activity among Samoan adults and highlights variation by sex, urbanicity, and weight status. In providing initial device-measured estimates of physical activity in Samoa, this analysis establishes a baseline from which the success of future attempts to intervene on physical activity may be assessed.

Epidemiology of chronic multimorbidity and temporary migration in a rural South African community in health transition: A cross-sectional population-based analysis.

Introduction: In sub-Saharan African settings, the increasing non-communicable disease mortality is linked to migration, which disproportionately exposes sub-populations to risk factors for co-occurring HIV and NCDs. Methods: We examined the prevalence, patterns, and factors associated with two or more concurrent diagnoses of chronic diseases (i.e., multimorbidity) among temporary within-country migrants. Employing a cross-sectional design, our study sample comprised 2144 residents and non-residents 18-40 years interviewed and with measured biomarkers in 2018 in Wave 1 of the Migrant Health Follow-up Study (MHFUS), drawn from the Agincourt Health and Demographic Surveillance System (AHDSS) in rural north-eastern South Africa. We used modified Poisson regression models to estimate the association between migration status and prevalent chronic multimorbidity conditional on age, sex, education, and healthcare utilisation. Results: Overall, 301 participants (14%; 95% CI 12.6-15.6), median age 31 years had chronic multimorbidity. Multimorbidity was more prevalent among non-migrants (14.6%; 95% CI 12.8-16.4) compared to migrants (12.8%; 95% CI 10.3-15.7). Non-migrants also had the greatest burden of dual-overlapping chronic morbidities, such as HIV-obesity 5.7%. Multimorbidity was 2.6 times as prevalent (PR 2.65. 95% CI 2.07-3.39) among women compared to men. Among migrants, men, and individuals with secondary or tertiary education manifested lower prevalence of two or more conditions. Discussion: In a rural community with colliding epidemics, we found low but significant multimorbidity driven by a trio of conditions: HIV, hypertension, and obesity. Understanding the multimorbidity burden associated with early adulthood exposures, including potential protective factors (i.e., migration coupled with education), is a critical first step towards improving secondary and tertiary prevention for chronic disease among highly mobile marginalised sub-populations.