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.

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.

Association between age at menarche and cardiometabolic risk among Samoan adults.

OBJECTIVES: Recent studies suggest that early menarche may increase cardiometabolic morbidity and mortality. Yet few studies have examined this association in the Pacific Islands, where obesity prevalence is among the highest globally. We sought to examine associations between age at menarche and cardiometabolic risk in Samoa. METHODS: Participants were from the Soifua Manuia study (n = 285, age 32-72 years) conducted in Samoa from 2017 to 2019. Logistic regressions were conducted to estimate odds of obesity, hypertension, diabetes, dyslipidemia, and metabolic syndrome per one-year increase in age at menarche. Linear regressions were conducted to examine associations between age at menarche and continuous measures of adiposity, blood pressure, insulin resistance, and serum lipids. RESULTS: Median age at menarche was 14 years (IQR = 2). After controlling for relevant covariates, each one-year increase in age at menarche was associated with a 15% decrease (OR = 0.85, 95% CI: 0.72-1.01, p = .067) in odds of hypertension, but a 21% increase (OR = 1.21, 95% CI: 1.01-1.45, p = .044) in odds of diabetes and 18% increase (OR = 1.18, 95% CI: 0.98-1.42, p = .081) in odds of high total cholesterol. Each additional year in age at menarche was associated with a 1.60 ± 0.52 kg (p = .002) decrease in lean mass and 1.56 ± 0.51 kg (p = .003) decrease in fat-free mass. CONCLUSIONS: Associations between age at menarche and cardiometabolic risk may be population-specific and are likely influenced by both current and historical nutritional and epidemiological contexts. Prospective studies are needed to clarify the role of childhood adiposity and other early life exposures on age at menarche and subsequent cardiometabolic risk.

Prevalence of malnutrition among Samoan children aged 5 to 11 years in 2019-2020.

BACKGROUND: Globally, rapid economic development, urbanisation, and nutrition transitions have led to rising levels of malnutrition in all forms. AIM: The study objective was to document the prevalence of overweight/obesity, underweight, stunting, and anaemia among Samoan children in 2019-2020. SUBJECTS AND METHODS: Children from the Ola Tuputupua'e "Growing Up" in Samoa study at ages 5-11 years with complete physical assessments were included. Overweight/obesity, underweight, and stunting were classified using World Health Organisation Z-scores for body mass index-for-age (BMIZ> +1), weight-for-age (WAZ< -2SD), and height-for-age (HAZ< -2SD), respectively. Anaemia was defined as haemoglobin concentration <11.5 g/dL. Prevalence was compared by child age, sex, and census region of residence (representing urbanicity and exposure to nutrition transition) using Wilcoxon two-sample, Chi-square, or Fisher's exact tests. RESULTS: The prevalence of overweight/obesity, underweight, stunting, and anaemia was 36.2%, 0.5%, 1.6%, and 31.6%, respectively. Overweight/obesity in children was positively associated with age and highly prevalent in periurban and urban regions. While children living in the rural region with the lowest exposure to nutrition transition had the highest prevalence of mild-to-moderate stunting, anaemia prevalence was lower compared to those in the urban region. No sex differences in malnutrition were observed. CONCLUSION: Moderate-to-high levels of overweight/obesity and anaemia call for comprehensive intervention strategies.

Prediction of fat mass from anthropometry at ages 7 to 9 years in Samoans: a cross-sectional study in the Ola Tuputupua'e cohort.

BACKGROUND/OBJECTIVE: With increasing obesity prevalence in children globally, accurate and practical methods for quantifying body fat are critical for effective monitoring and prevention, particularly in high-risk settings. No population is at higher risk of obesity than Pacific Islanders, including children living in the independent nation of Samoa. We developed and validated sex-specific prediction models for fat mass in Samoan children. SUBJECTS/METHODS: Dual X-ray absorptiometry (DXA) assessments of fat mass and weight, height, circumferences, and skinfolds were obtained from 356 children aged 7-9 years old in the Ola Tuputupua'e "Growing Up" study. Sex-specific models were developed from a randomly selected model development sample (n = 118 females, n = 120 males) using generalized linear regressions. In a validation sample (n = 59 females; n = 59 males), Lin's concordance and Bland-Altman limits-of-agreement (LoA) of DXA-derived and predicted fat mass from this study and other published models were examined to assess precision and accuracy. RESULTS: Models to predict fat mass in kilograms were: e^[(-0.0034355 * Age8 - 0.0059041 * Age9 + 1.660441 * ln (Weight (kg))-0.0087281 * Height (cm) + 0.1393258 * ln[Suprailiac (mm)] - 2.661793)] for females and e^[-0.0409724 * Age8 - 0.0549923 * Age9 + 336.8575 * [Weight (kg)]-2 - 22.34261 * ln (Weight (kg)) [Weight (kg)]-1 + 0.0108696 * Abdominal (cm) + 6.811015 * Subscapular (mm)-2 - 8.642559 * ln (Subscapular (mm)) Subscapular (mm)-2 - 1.663095 * Tricep (mm)-1 + 3.849035]for males, where Age8 = Age9 = 0 for children at age 7 years, Age8 = 1 and Age9 = 0 at 8 years, Age8 = 0 and Age9 = 1 at 9 years. Models showed high predictive ability, with substantial concordance (ρC > 0.96), and agreement between DXA-derived and model-predicted fat mass (LoA female = -0.235, 95% CI:-2.924-2.453; male = -0.202, 95% CI:-1.977-1.572). Only one of four existing models, developed in a non-Samoan sample, accurately predicted fat mass among Samoan children. CONCLUSIONS: We developed models that predicted fat mass in Samoans aged 7-9 years old with greater precision and accuracy than the majority of existing models that were tested. Monitoring adiposity in children with these models may inform future obesity prevention and interventions.

Whole genome sequence analysis of blood lipid levels in >66,000 individuals.

Blood lipids are heritable modifiable causal factors for coronary artery disease. Despite well-described monogenic and polygenic bases of dyslipidemia, limitations remain in discovery of lipid-associated alleles using whole genome sequencing (WGS), partly due to limited sample sizes, ancestral diversity, and interpretation of clinical significance. Among 66,329 ancestrally diverse (56% non-European) participants, we associate 428M variants from deep-coverage WGS with lipid levels; ~400M variants were not assessed in prior lipids genetic analyses. We find multiple lipid-related genes strongly associated with blood lipids through analysis of common and rare coding variants. We discover several associated rare non-coding variants, largely at Mendelian lipid genes. Notably, we observe rare LDLR intronic variants associated with markedly increased LDL-C, similar to rare LDLR exonic variants. In conclusion, we conducted a systematic whole genome scan for blood lipids expanding the alleles linked to lipids for multiple ancestries and characterize a clinically-relevant rare non-coding variant model for lipids.

Is overweight or obesity associated with anemia in children? Follow-up of Samoans in the Ola Tuputupua'e "Growing Up" study.

OBJECTIVES: Globally, there is growing evidence of a double burden of malnutrition with obesity coexisting alongside micronutrient deficiencies across the life course. An emergent double burden poses a threat to health during childhood in Samoa: among 2-4-year-olds with overweight/obesity, 42.9% were anemic. Previous research suggests that obesity-related inflammation may increase the risk of iron deficiency or anemia in children. To test this hypothesis, we examined whether overweight/obesity at 2-4 is associated with anemia at 3.8-6 years old among Samoan children. METHODS: Data were obtained from the Ola Tuputupua'e "Growing Up" cohort study. Overweight/obesity at 2-4 years old was classified by body mass index-for-age Z-score > +2 SD. Anemia was defined as hemoglobin < 110 g/L for under 5-year-olds and < 115 g/L for 5-6-year-olds. Prevalence ratios (PRs) for anemia at 3.8-6 years old were estimated by fitting modified Poisson regression models. RESULTS: In our sample of 197 children, 16.24% (n = 32) were affected by overweight/obesity at 2-4 years old and 26.90% (n = 53) had anemia at 3.8-6 years old. After covariate adjustment, the prevalence of anemia was 18% lower among children with overweight/obesity at 2-4 years old compared to those without (PR:0.82; 95% CI:0.42-1.63); however, the corresponding confidence interval was imprecise and inclusive of a higher prevalence. CONCLUSIONS: There was not strong evidence to support a relationship between overweight/obesity and anemia in Samoan children, suggesting that obesity-related inflammation may not be related to iron deficiency nor anemia in this setting. Further investigation of the antecedents of overweight/obesity and anemia is critical to inform integrated action to improve health in Samoa.

Persistence of anaemia among Samoan preschool age children: a longitudinal study.

OBJECTIVE: To characterise the prevalence and persistence of anaemia among Samoan children over a 2-3-year period. DESIGN: Data were from two consecutive waves (2015 and 2017-2018) of the Ola Tuputupua'e 'Growing up' study. Anaemia (Hb < 11·0 or 11·5 g/dl for 2-4 and ≥ 5 years old, respectively) was considered 'transient' when it occurred at only one wave or 'persistent' if it was present at two consecutive waves. Child, maternal and household correlates of anaemia were examined using log-binomial and modified Poisson regressions. SETTING: Eleven Samoan villages. PARTICIPANTS: Mother-child pairs (n 257) recruited in 2015 and reassessed in 2017-2018. RESULTS: Anaemia prevalence was 33·9 % in 2015 and 28·0 % in 2017-2018; 35·6 % of cases identified in 2015 were persistent. Risk of anaemia at only one wave was lower among children who were older in 2015 (age 4 v. 2 years, adjusted relative risk (aRR) = 0·54, (95 % CI 0·35, 0·84), P = 0·007), had older mothers (≥ 40 v. 18-29 years, aRR = 0·61, (95 % CI 0·39, 0·95), P = 0·029) and had higher daily sodium intake (for every 100 mg/d, aRR = 0·97, (95 % CI 0·95, 0·99), P = 0·003) than children with no anaemia. Children whose anaemia persisted were more likely to have had a mother with anaemia (aRR = 2·13, (95 % CI 1·17, 3·89), P = 0·013) and had higher daily dietary iron intake (for every 10 mg/d, aRR = 4·69, (95 % CI 1·33, 16·49), P = 0·016) than those with no anaemia. CONCLUSIONS: Alongside broadly targeted prevention efforts, which are warranted given the moderate-high anaemia prevalence observed, specific attention should be paid to children with risk factors for persistent anaemia. Routine screening of children whose mothers have anaemia should be encouraged.

Comparability of The Netherlands Physical Activity Questionnaire with Accelerometer-Measured Physical Activity in Samoan Children: A Retrospective Analysis of Ola Tuputupua'e Data.

Accurate measurement of physical activity is critical to understand its role in cardiometabolic health and obesity development in children and to monitor trends in behavior and evaluate interventions. An ongoing mixed-longitudinal study of child growth and development in Samoa is collecting physical activity data with both accelerometers and the Netherlands Physical Activity Questionnaire (NPAQ). The aims of our analyses were to (1) describe the response frequency and correlations of individual questions in the NPAQ, (2) develop modified NPAQ scores with selected questions and (3) examine the concordance of modified NPAQ scores with accelerometer outcomes among children aged 2-4 years. We developed two modified NPAQ scores with combinations of questions and assessed concordance of the modified scores with accelerometer data using estimated marginal means adjusted for monitor wear time. Although the evenly distributed tertiles of the modified 15-point NPAQ score showed promising trends of increasing minutes of accelerometer-assessed high-intensity physical activity with increasing tertile, the estimated marginal means were imprecise with high variance, demonstrating that NPAQ score could not accurately assess physical activity levels of preschool-aged children in Samoa. Considering that questionnaires are often considered more cost-effective tools for physical activity measurement than accelerometry, further research is necessary to develop a culturally and age-appropriate physical activity questionnaire in this population.

Longitudinal Assessment of Childhood Dietary Patterns: Associations with Body Mass Index z-Score among Children in the Samoan Ola Tuputupua'e (Growing Up) Cohort.

Background: Intervention strategies to prevent childhood obesity in the Pacific Islands encourage eating a variety of local and traditional foods, but context-specific data to support this approach are limited. The objective was to assess the association between 2-year adherence to modern and neotraditional dietary patterns and body mass index z-scores (BMIz) among Samoan children. Methods: A convenience sample of 214 Samoan biological mother-child dyads who participated in the Ola Tuputupua'e "Growing Up" cohort study in 2015 and 2017 was included. At each time point, modern and neotraditional dietary patterns were identified using food frequency data and factor analysis. Children were assigned to categories based on diet pattern adherence: consistently high, high to low, low to high, and consistently low. Associations between 2-year adherence to dietary patterns, BMIz (in 2017 and 2015-2017), and weight and height z-scores were examined using linear models adjusted for potential confounders. Results: Consistently high adherence to the modern pattern was associated with a 0.36 standard deviation (SD)-adjusted change in BMIz between 2015 and 2017 (95% confidence interval [CI]: 0.04-0.69, p = 0.03). While the estimates for the individual components of BMI were imprecise, on average, children with consistently high adherence to the modern pattern had a 0.13 SD greater change in weight z-score (95% CI: -0.10 to 0.37) and 0.15 SD lower change in height z-score (95% CI: -0.43 to 0.13). The change in BMIz between 2015 and 2017 did not significantly differ by adherence to the neotraditional pattern. Conclusion: A neotraditional dietary pattern, comprising local produce, should be encouraged as a possible childhood obesity prevention strategy in Samoa.

Piloting a food photo sorting activity in Samoa to assess maternal beliefs and their role in child diet.

Eating habits begin forming early in life when parental beliefs and behaviours often play a major role in shaping dietary intake. We aimed to assess maternal beliefs about the cost, social status, and nutritional value of foods in Samoa-a setting with an alarming burden of childhood obesity-and to determine how those beliefs may be related to child dietary intake. Samoan mothers (n = 44) sorted photographs of 26 foods commonly consumed in children in Samoa by cost, social status, and nutritional value (healthfulness). Responses were then assessed for their association with child dietary intake (reported using a food frequency questionnaire) using Pearson correlations. Mothers indicated that traditional Samoan foods were healthier, of higher social status, and lower cost compared with non-traditional/imported food items. Compared with nutritional experts and a market survey of food prices, mothers demonstrated strong nutritional (r = .87, 95% CI [0.68, 0.95], p < .001) and consumer (r = .84, 95% CI [0.68, 0.93], p < .001) knowledge. The perceived cost of food was more strongly associated (r = -.37, 95% CI [-0.66, 0.02], p = .06) with child dietary intake than either healthfulness or social status, with decreasing consumption reported with increasing food cost. Our findings contradicted the notion that the high social status of imported foods may be contributing to increased intake and rising prevalence of childhood obesity in this developing country setting. Despite their nutritional knowledge, Samoan mothers may need additional support in applying their knowledge/beliefs to provide a healthy child diet, including support for access to reasonably priced healthy foods.

Changing body norms in the context of increasing body size: Samoa in 1995 and 2018.

OBJECTIVE: To understand how body size preferences changed in Samoa between 1995 and 2017 to 2019. METHODS: Data were from adults aged from 31 to 59 years, who participated in two separate cross-sectional studies of obesity and cardiometabolic risk conducted in Samoa in 1995 and 2017 to 2019. Participants nominated line drawings representing their current size, ideal size, the most attractive and healthiest size, and the lower/upper limits of "normal" size. RESULTS: In both sexes, body size preferences and perceived current average body size have increased, yet preference for bodies smaller than one's perceived current size has persisted. Furthermore, the range of body sizes that people considered "normal" has narrowed, suggesting decreased tolerance for extremes of body size. CONCLUSIONS: These findings may have implications for mental and physical health outcomes, inform development of future health initiatives, and contribute to a deeper understanding of how body norms and weight-related public health efforts interface.

Nutrient intake among Samoan children aged 2-4 years in 2015.

BACKGROUND: Young children are particularly vulnerable to malnutrition as nutrition transition progresses. The aim of this study was to examine the adequacy of macro- and micronutrient intake among 2-4.99-year-old Samoan children. METHODS: Child dietary intake was measured using a 117-item food frequency questionnaire (FFQ) with a 30-day reference period. Daily total energy and nutrient intake was calculated by multiplying the frequency of daily consumption by the nutrient content of a fixed, standard portion size. Adequacy of macro- and micronutrient intake was determined using age-specific US Dietary Guidelines. RESULTS: Most children met or exceeded recommendations for carbohydrate, fat and protein intake. More than half of the sample were not meeting the Recommended Dietary Allowance (RDA) for calcium (59.0%), 44.6% were not meeting RDA for potassium and intake of vitamin A and E was inadequate among 25.9% and 25.6%, respectively. Eighty per cent of children exceeded the tolerable upper limit for sodium. Adequacy of intake varied by age and census region of residence. CONCLUSION: Since inadequate dietary micronutrient intake was more common among older children (4-4.99 years) and those in the rural region, intervention should be targeted at those groups.

Dietary patterns are associated with child, maternal and household-level characteristics and overweight/obesity among young Samoan children.

OBJECTIVE: Among young Samoan children, diet may not be optimal: in 2015, 16·1 % of 24-59-month-olds were overweight/obese, 20·3 % stunted and 34·1 % anaemic. The present study aimed to identify dietary patterns among 24-59-month-old Samoan children and evaluate their association with: (i) child, maternal and household characteristics; and (ii) nutritional status indicators (stunting, overweight/obesity, anaemia). DESIGN: A community-based, cross-sectional study. Principal component analysis on 117 FFQ items was used to identify empirical dietary patterns. Distributions of child, maternal and household characteristics were examined by factor score quintiles. The regression of nutritional status indicators v. these quintiles was performed using logistic regression models. SETTING: Ten villages on the Samoan island of Upolu. SUBJECTS: A convenience sample of mother-child pairs (n 305). RESULTS: Two dietary patterns, modern and neo-traditional, emerged. The modern pattern was loaded with 'westernized' foods (red meat, condiments and snacks). The neo-traditional pattern included vegetables, local starches, coconuts, fish and poultry. Following the modern diet was associated with urban residence, greater maternal educational attainment, higher socio-economic status, lower vitamin C intake and higher sugar intake. Following the neo-traditional diet was associated with rural residence, lower socio-economic status, higher vitamin C intake and lower sugar intake. While dietary patterns were not related to stunting or anaemia, following the neo-traditional pattern was positively associated with child overweight/obesity (adjusted OR=4·23, 95 % CI 1·26, 14·17, for the highest quintile, P-trend=0·06). CONCLUSIONS: Further longitudinal monitoring and evaluation of early childhood growth and development are needed to understand the influences of early diet on child health in Samoa.

Child, maternal and household-level correlates of nutritional status: a cross-sectional study among young Samoan children.

OBJECTIVE: Young children are particularly vulnerable to malnutrition as nutrition transition progresses. The present study aimed to document the prevalence, coexistence and correlates of nutritional status (stunting, overweight/obesity and anaemia) in Samoan children aged 24-59 months. DESIGN: A cross-sectional community-based survey. Height and weight were used to determine prevalence of stunting (height-for-age Z-score +2) based on WHO growth standards. Anaemia was determined using an AimStrip Hemoglobin test system (Hb <110 g/l). SETTING: Ten villages on the Samoan island of Upolu. SUBJECTS: Mother-child pairs (n 305) recruited using convenience sampling. RESULTS: Moderate or severe stunting was apparent in 20·3 % of children, 16·1 % were overweight/obese and 34·1 % were anaemic. Among the overweight/obese children, 28·6 % were also stunted and 42·9 % anaemic, indicating dual burden of malnutrition. Stunting was significantly less likely among girls (OR=0·41; 95 % CI 0·21, 0·79, P<0·01) than boys. Overweight/obesity was associated with higher family socio-economic status and decreased sugar intake (OR per 10 g/d=0·89, 95 % CI 0·80, 0·99, P=0·032). The odds of anaemia decreased with age and anaemia was more likely in children with an anaemic mother (OR=2·20; 95 % CI 1·22, 3·98, P=0·007). No child, maternal or household characteristic was associated with more than one of the nutritional status outcomes, highlighting the need for condition-specific interventions in this age group. CONCLUSIONS: The observed prevalences of stunting, overweight/obesity and anaemia suggest that it is critical to invest in nutrition and develop health programmes targeting early childhood growth and development in Samoa.