Continued increases in blood pressure over two decades in Samoa (1991-2013); around one-third of the increase explained by rising obesity levels

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.

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.

Effects of inappropriate cause-of-death certification on mortality from cardiovascular disease and diabetes mellitus in Tonga

BACKGROUND

Cardiovascular disease (CVD) and diabetes mellitus are major health issues in Tonga and other Pacific countries, although mortality levels and trends are unclear. We assess the impacts of cause-of-death certification on coding of CVD and diabetes as underlying causes of death (UCoD).

METHODS

Tongan records containing cause-of-death data (2001-2018), including medical certificates of cause-of-death (MCCD), had UCoD assigned according to International Classification of Diseases 10th revision (ICD-10) coding rules. Deaths without recorded cause were included to ascertain total mortality. Diabetes and hypertension causes were reallocated from Part 1 of the MCCD (direct cause) to Part 2 (contributory cause) if potentially fatal complications were not recorded, and an alternative UCoD was assigned. Proportional mortality by cause based on the alternative UCoD were applied to total deaths then mortality rates calculated by age and sex using census/intercensal population estimates. CVD and diabetes mortality rates for unaltered and alternative UCoD were compared using Poisson regression.

RESULTS

Over 2001-18, in ages 35-59 years, alternative CVD mortality was higher than unaltered CVD mortality in men (p = 0.043) and women (p = 0.15); for 2010-18, alternative versus unaltered measures in men were 3.3/103 (95%CI: 3.0-3.7/103) versus 2.9/103 (95%CI: 2.6-3.2/103), and in women were 1.1/103 (95%CI: 0.9-1.3/103) versus 0.9/103 (95%CI: 0.8-1.1/103). Conversely, alternative diabetes mortality rates were significantly lower than the unaltered rates over 2001-18 in men (p < 0.0001) and women (p = 0.013); for 2010-18, these measures in men were 1.3/103 (95%CI: 1.1-1.5/103) versus 1.9/103 (95%CI: 1.6-2.2/103), and in women were 1.4/103 (95%CI: 1.2-1.7/103) versus 1.7/103 (95%CI: 1.5-2.0/103). Diabetes mortality rates increased significantly over 2001-18 in men (unaltered: p < 0.0001; alternative: p = 0.0007) and increased overall in women (unaltered: p = 0.0015; alternative: p = 0.014).

CONCLUSIONS

Diabetes reporting in Part 1 of the MCCD, without potentially fatal diabetes complications, has led to over-estimation of diabetes, and under-estimation of CVD, as UCoD in Tonga. This indicates the importance of controlling various modifiable risks for atherosclerotic CVD (including stroke) including hypertension, tobacco use, and saturated fat intake, besides obesity and diabetes. Accurate certification of diabetes as a direct cause of death (Part 1) or contributory factor (Part 2) is needed to ensure that valid UCoD are assigned. Examination of multiple cause-of-death data can improve understanding of the underlying causes of premature mortality to better inform health planning.

Results of a community-based screening programme for chronic kidney disease and associated risk factors, (obesity, diabetes and hypertension) in a Samoan cohort

OBJECTIVES

In 2019, under the World Kidney Day theme of 'Kidney health for everyone everywhere', the National Kidney Foundation of Samoa undertook an extensive community screening campaign to detect the estimated prevalence of chronic kidney disease (CKD) and its associated risk factors in the community.

SETTING

Fifteen screening sites, with 11 urban and rural sites on the main island of Upolu, and 4 in different rural areas on the island of Savaii.

PARTICIPANTS

All participants were self-referrals to the various screening sites. In total, 1163 Samoans were screened, with similar numbers from both urban and rural areas and similar numbers of female and male.

SCREENING ACTIVITIES

All participants were screened for CKD using point of care serum creatinine determinations, with calculation of estimated glomerular filtration rate using the CKD-EPI formula and dipstix urinalysis. A standardised screening survey was used to capture demographic and medical history with associated risk factors of obesity, diabetes, using point of care determination of HbA1c and hypertension. Logistic regression was used to investigate the association of CKD with risk factors.

RESULTS

In total, 1163 people were screened for CKD within the month of March 2019. The prevalance of CKD (grades 1-5) was 44.5% (95% CI 41.6% to 47.4) with individual grade prevalence CKD 1: 3.7%, CKD 2: 6.1%, CKD 3: 30.7%, CKD 4: 2.9% and CKD 5: 1.0%. The prevalence of obesity (body mass index ≥32), diabetes and hypertension was 66.3%, 30.8% and 54.3%, respectively.

CONCLUSIONS

This is the first paper to report the estimated prevalence of CKD in Samoa or any other Pacific Island nation. It reveals an urgent need for further studies on the epidemiology of CKD in Samoa, to develop country-specific prevention strategies to mitigate this growing burden and prevent subsequent CKD associated complications including development of kidney failure and premature death.

Scaling-up food policies in the Pacific Islands: protocol for policy engagement and mixed methods evaluation of intervention implementation

BACKGROUND

There is a crisis of non-communicable diseases (NCDs) in the Pacific Islands, and poor diets are a major contributor. The COVID-19 pandemic and resulting economic crisis will likely further exacerbate the burden on food systems. Pacific Island leaders have adopted a range of food policies and regulations to improve diets. This includes taxes and regulations on compositional standards for salt and sugar in foods or school food policies. Despite increasing evidence for the effectiveness of such policies globally, there is a lack of local context-specific evidence about how to implement them effectively in the Pacific.

METHODS

Our 5-year collaborative project will test the feasibility and effectiveness of policy interventions to reduce salt and sugar consumption in Fiji and Samoa, and examine factors that support sustained implementation. We will engage government agencies and civil society in Fiji and Samoa, to support the design, implementation and monitoring of evidence-informed interventions. Specific objectives are to: (1) conduct policy landscape analysis to understand potential opportunities and challenges to strengthen policies for prevention of diet-related NCDs in Fiji and Samoa; (2) conduct repeat cross sectional surveys to measure dietary intake, food sources and diet-related biomarkers; (3) use Systems Thinking in Community Knowledge Exchange (STICKE) to strengthen implementation of policies to reduce salt and sugar consumption; (4) evaluate the impact, process and cost effectiveness of implementing these policies. Quantitative and qualitative data on outcomes and process will be analysed to assess impact and support scale-up of future interventions.

DISCUSSION

The project will provide new evidence to support policy making, as well as developing a low-cost, high-tech, sustainable, scalable system for monitoring food consumption, the food supply and health-related outcomes.

Cascades of diabetes and hypertension care in Samoa: Identifying gaps in the diagnosis, treatment, and control continuum - a cross-sectional study

BACKGROUND

Samoa is a Pacific Island country facing one of the highest burdens of non-communicable disease globally.

METHODS

In this study, we apply a cascade-of-care approach to understand gaps in the awareness, treatment, and control cascade of diabetes and hypertension in a cross-sectional, convenience sample of 703 young, high-risk Samoan adults (29.5-50.9 years).

FINDINGS

Non-communicable diseases were prevalent in the study sample: 19.5% (95% CI: 16.6%-22.7%) of participants had diabetes; 47.6% (95% CI: 43.7%-51.4%) presented with pre-diabetes or diabetes; 31.0% (95% CI: 27.5%-34.6%) had hypertension; and nearly 90% (95% CI: 86.7%-91.5%) had overweight or obesity. Among those with diabetes and hypertension, only 20.5% (95% CI: 13.9%-28.4%) and 11.8% (95% CI: 7.8%-16.9%) of participants were aware of their condition, respectively. Only 0.8% (95% CI: 0.0%-4.2%) of all participants with diabetes had achieved glycemic control; only 2.8% (95% CI: 1.1%-6.1%) of those with hypertension achieved control.

INTERPRETATION

We found a significant burden of diabetes and hypertension in Samoa, exceeding the recent prevalence estimates of other low- to middle-income countries by nearly two-fold. A severe unmet need in both detection and subsequent control and monitoring of these chronic conditions exists. Our results suggest that the initial diagnosis and surveillance stage in the cascade of care for chronic conditions should be a major focus of primary care efforts; national screening campaigns and programs that leverage village and district nurses to deliver community-based primary care may significantly impact gap closure in the NCD cascade.

FUNDING

This study was supported by the U.S. National Institutes of Health R01HL140570 (PIs: McGarvey and DeLany); AR was supported by NIH FIC D43TW010540; HK and AR-C were supported by the Minority Health and Health Disparities International Research Training (MHIRT) Program at Brown University, NIH Grant # 5T37MD008655.

The CREBRF diabetes-protective rs373863828-A allele is associated with enhanced early insulin release in men of Māori and Pacific ancestry

AIMS/HYPOTHESIS

The minor A allele of rs373863828 (CREBRF p.Arg457Gln) is associated with increased BMI, but reduced risk of type 2 and gestational diabetes in Polynesian (Pacific peoples and Aotearoa New Zealand Māori) populations. This study investigates the effect of the A allele on insulin release and sensitivity in overweight/obese men without diabetes.

METHODS

A mixed meal tolerance test was completed by 172 men (56 with the A allele) of Māori or Pacific ancestry, and 44 (24 with the A allele) had a frequently sampled IVGTT and hyperinsulinaemic-euglycaemic clamp. Mixed linear models with covariates age, ancestry and BMI were used to analyse the association between the A allele of rs373863828 and markers of insulin release and blood glucose regulation.

RESULTS

The A allele of rs373863828 is associated with a greater increase in plasma insulin 30 min following a meal challenge without affecting the elevation in plasma glucose or incretins glucagon-like polypeptide-1 or gastric inhibitory polypeptide. Consistent with this point, following an i.v. infusion of a glucose bolus, participants with an A allele had higher early (p < 0.05 at 2 and 4 min) plasma insulin and C-peptide concentrations for a similar elevation in blood glucose as those homozygous for the major (G) allele. Despite increased plasma insulin, rs373863828 genotype was not associated with a significant difference (p > 0.05) in insulin sensitivity index or glucose disposal during hyperinsulinaemic-euglycaemic clamp.

CONCLUSIONS/INTERPRETATION

rs373863828-A allele associates with increased glucose-stimulated insulin release without affecting insulin sensitivity, suggesting that CREBRF p.Arg457Gln may increase insulin release to reduce the risk of type 2 diabetes.

Assessing the impact of high blood pressure referrals on hypertension awareness and management, BMI, and blood pressure values in adult Samoans 2010-2019

The Samoan population has experienced rapid increases in the prevalence of non-communicable diseases (NCDs) and NCD risk factors over the last 30 years. However, understanding how increased awareness and treatment of these conditions in reducing disease burden remains understudied. Using data from a longitudinal study (2010-2019) of cardiometabolic health among Samoan adults, we assess the impact of a referral for elevated blood pressure (BP) on changes in BP, physician's diagnoses of hypertension and medication use, body mass index (BMI), and other risk factors for elevated BP. Analyses compared adult Samoans (n = 328) who in 2010 either (1) received a referral for elevated BP (BP ≥ 140/90 mmHg) or (2) had measured BP indicative of pre-hypertension (BP ≥ 120/80 mmHg) but were not referred. Data were analysed using linear and logistic regression, paired T- and McNemar's tests, and Wilcoxon Rank Sum assessments. Referrals in 2010 significantly increased the odds of reporting a physician's diagnosis of hypertension (OR 2.16; 1.18, 3.95) and hypertension medication use (OR 3.52; 1.86, 6.73) in 2018; however, referrals, medication use, and diagnoses were not associated with BP values or reduced odds of having elevated BP. Despite the referral having positive effects on hypertension-related health care, our results demonstrate that other factors are influencing effective BP/hypertension control. We advocate for greater engagement of health researchers with local health sector actors to improve the probability that researcher-provided health referrals will result in long-term health improvements.