Adil Supiyev

Objectives. Evidence on cognitive performance among older adults in Kazakhstan and Central Asia remains limited. This study aimed to establish normative values for neuropsychological tests among adults living in urban and rural areas of Kazakhstan, stratified by age and educational attainment. Methods. This cross-sectional study included 1,648 adults aged 50–75 years randomly selected from urban and rural communities in Central and East Kazakhstan between 2012 and 2016. Four standardized neuropsychological tests assessed verbal memory and learning, verbal fluency, attention, and concentration. Normative values were calculated separately by urban-rural residence, age group, and educational level. Results. Cognitive performance generally declined with increasing age and was higher among participants with greater educational attainment. Urban residents demonstrated higher mean scores than rural residents on immediate word recall (18.98 vs. 16.49), animal naming (18.17 vs. 16.37), and delayed word recall (6.32 vs. 5.71), whereas rural residents scored higher on letter cancellation (22.06 vs. 19.76; all p < 0.001). Age-, education-, and residence-specific percentile norms were established for all four cognitive tests. Discussion. This study provides some of the first population-based normative data for multiple cognitive domains among urban and rural adults in Kazakhstan. These reference values may support the interpretation of cognitive assessments in comparable Central Asian populations, although further validation and studies involving older age groups are needed.

Introduction: There is limited information on cardiometabolic risk factors in Central Asia. This study examined the prevalence of overweight, obesity, and central obesity and assessed socioeconomic and demographic correlates among older adults in urban and rural areas of the Astana region of Kazakhstan. Methods: This cross-sectional study included 977 adults aged 50 to 74 years recruited from urban (Astana) and rural (Akmol) sites in the Astana region of Kazakhstan. Multivariable binary logistic regression analyses with three sequential models were conducted to examine associations between obesity measures, socioeconomic characteristics, and cardiometabolic conditions. Robust standard errors were used throughout. Results: Overall, 37% of participants were overweight, 44% were obese, and 72% had central obesity. Overweight and central obesity were more prevalent in men, while BMI-defined obesity was more common in women (52% vs. 34%). All three obesity measures were significantly and consistently associated with diabetes, hypertension, and hypercholesterolemia across all models. Rural residence was strongly protective against central obesity across all models (fully adjusted OR, 0.43; 95% CI, 0.30–0.64). Greater household asset ownership was positively associated with overweight and obesity in a dose–response fashion, with a significant linear trend confirmed for both outcomes (p for trend = 0.038 and p = 0.002, respectively), suggesting a reversed socioeconomic gradient consistent with an early-stage nutrition transition. Educational attainment showed a more complex pattern, with lower education associated with higher odds of obesity in the fully adjusted model. Older age was associated with greater odds of central obesity. Conclusion: Obesity is highly prevalent among older adults in the Astana region of Kazakhstan. In contrast to the inverse socioeconomic gradient commonly observed in high-income settings, household asset ownership showed a reversed gradient: more affluent participants had significantly higher odds of obesity, whereas lower educational attainment was associated with higher obesity risk. The strong associations between all obesity measures and cardiometabolic conditions underscore the urgent need for integrated obesity and cardiometabolic disease prevention strategies. These findings highlight the need for context-specific public health approaches that account for the distinct socioeconomic patterning of obesity in Kazakhstan.

Handgrip strength (HGS) is a key indicator of health. However, it remains understudied in low-income rural populations in Ecuadori. To analyze the associations between sociodemographic and health conditions and HGS in adults aged 55 years and older living in rural areas of Ecuador. This cross-sectional study included 258 participants aged 55 years or older. Univariate and multivariate linear regression models were used to examine the associations between HGS and sociodemographic variables, as well as health and physical function indicators. Ecuadorians mean HGS of the sample (n = 258) was 24.0 ± 7.7 kg. Men had significantly higher HGS than women (28.6 ± 8.1 kg vs 20.5 ± 5.0 kg; β = 8.56, p < 0.001). In the fully adjusted model (adjusted R² = 0.55; F = 16.21, p < 0.001), higher HGS was independently associated with male sex (β = 8.56, p < 0.001), higher educational level (β = 3.44, p = 0.029), being retired (β = 2.11, p = 0.043), and normal walking speed (β = 2.04, p = 0.028), while age showed a negative association (β = − 0.35, p < 0.001). Income, physical activity, and multimorbidity were not significantly associated with HGS. HGS is associated with key sociodemographic and functional factors in adults from rural areas of Ecuador. These findings support its usefulness as a simple and relevant indicator of functional health in resource-limited settings.

Background: Chronic stress and dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis may influence oral health, yet evidence linking long-term glucocorticoid exposure to dental caries in adolescents remains limited. Hair cortisol and cortisone provide integrated biomarkers of chronic HPA-axis activity, and their ratio reflects glucocorticoid metabolic balance and 11β-hydroxysteroid dehydrogenase activity, which may be influenced by chronic stress-related physiological dysregulation. The objective was to examine the association between hair cortisol, cortisone, and their ratio with dental caries prevalence and severity in adolescents. Methods: This secondary cross-sectional analysis included 550 adolescents aged 14–15 years from the Kazakhstan Adolescent Health Study. Dental caries was assessed using the DMFT index. Hair glucocorticoid concentrations were measured by liquid chromatography-mass spectrometry, log-transformed, and the cortisol-to-cortisone ratio (CCR) was standardized (z-score). Multivariable logistic regression estimated odds ratios across hierarchical models adjusting for sociodemographic, socioeconomic, and behavioral factors, with school region as a fixed effect and robust standard errors. Zero-inflated negative binomial (ZINB) models examined associations with caries count. Results: Among 550 participants, 84% had DMFT ≥ 1. Although unadjusted analyses did not show significant differences in CCR by caries status ( p = 0.079), higher standardized CCR was associated with increased odds of dental caries after multivariable adjustment (OR = 1.40, 95% CI: 1.04–1.89 per SD increase). Results were consistent across sensitivity analyses, including Firth’s penalized logistic regression (OR = 1.36, 95% CI: 1.01–1.85). In ZINB analyses, CCR was not significantly associated with caries count. Individual glucocorticoids showed weaker, less consistent associations than their ratio. Conclusions: In this cross-sectional sample, higher CCR was associated with greater odds of dental caries after adjustment for measured covariates. Although elevated CCR may reflect physiological dysregulation associated with chronic stress, it should not be interpreted as a direct measure of stress. These findings are exploratory, require cautious interpretation given the cross-sectional design and absence of a significant unadjusted association, and need confirmation in longitudinal studies.

Objective The oral microbiome is one of the most complex microbial ecosystems in the host. This study aimed to investigate and characterize the oral microbiome composition in Kazakhstani adolescents associated with dental caries. Methodology The study included 312 adolescents, with 241 individuals presenting with caries and 71 caries-free, aged 12-15 years. Dental caries assessment was performed using DMFT (Decayed, missed, filled teeth) index. Oral samples were collected, and 16S rRNA (16S ribosomal ribonucleic acid) gene sequencing targeting the V3-V4 hypervariable regions on an Illumina MiSeq platform was performed to profile the microbial communities. Functional metagenomic predictions were generated using PICRUSt2 v2.5.0, using the KEGG database for bacterial pathway abundance estimation. Data analysis was conducted using Python 3.9.16 and R 4.2.2. Results The alpha diversity was insignificant, while beta diversity analysis demonstrated clear distinctions by Bray-Curtis (F=2.5, p=0.003) and weighted UniFrac distances (F=4.4, p=0.002). The Neisseria and Prevotella genera, and Gammaproteobacteria class showed significant associations with dental caries (MaAsLin2 p≤0.05, LDA≥2), stronger predictive power (AUC=0.65, F1=0.83), and higher predicted functional activity through glutathione metabolism, RNA degradation, and unsaturated fatty acid metabolism pathways. Conclusions This study identified specific oral microbiome patterns associated with dental caries in Kazakhstani adolescents, revealing interactions between key bacterial taxa and metabolic pathways.

Background: Global cardiovascular disease (CVD) burden is high and rising, especially in low-income and middle-income countries (LMICs). Focussing on 45 LMICs, we aimed to determine (1) the adult population’s median 10-year predicted CVD risk, including its variation within countries by socio-demographic characteristics, and (2) the prevalence of self-reported blood pressure (BP) medication use among those with and without an indication for such medication as per World Health Organization (WHO) guidelines. Methods and findings: We conducted a cross-sectional analysis of nationally representative household surveys from 45 LMICs carried out between 2005 and 2017, with 32 surveys being WHO Stepwise Approach to Surveillance (STEPS) surveys. Country-specific median 10-year CVD risk was calculated using the 2019 WHO CVD Risk Chart Working Group non-laboratory-based equations. BP medication indications were based on the WHO Package of Essential Noncommunicable Disease Interventions guidelines. Regression models examined associations between CVD risk, BP medication use, and socio-demographic characteristics. Our complete case analysis included 600,484 adults from 45 countries. Median 10-year CVD risk (interquartile range [IQR]) for males and females was 2.7% (2.3%–4.2%) and 1.6% (1.3%–2.1%), respectively, with estimates indicating the lowest risk in sub-Saharan Africa and highest in Europe and the Eastern Mediterranean. Higher educational attainment and current employment were associated with lower CVD risk in most countries. Of those indicated for BP medication, the median (IQR) percentage taking medication was 24.2% (15.4%–37.2%) for males and 41.6% (23.9%–53.8%) for females. Conversely, a median (IQR) 47.1% (36.1%–58.6%) of all people taking a BP medication were not indicated for such based on CVD risk status. There was no association between BP medication use and socio-demographic characteristics in most of the 45 study countries. Study limitations include variation in country survey methods, most notably the sample age range and year of data collection, insufficient data to use the laboratory-based CVD risk equations, and an inability to determine past history of a CVD diagnosis. Conclusions: This study found underuse of guideline-indicated BP medication in people with elevated CVD risk and overuse by people with lower CVD risk. Country-specific targeted policies are needed to help improve the identification and management of those at highest CVD risk.

Background: Cardiovascular diseases are leading causes of death, globally, and health systems that deliver quality clinical care are needed to manage an increasing number of people with risk factors for these diseases. Indicators of preparedness of countries to manage cardiovascular disease risk factors (CVDRFs) are regularly collected by ministries of health and global health agencies. We aimed to assess whether these indicators are associated with patient receipt of quality clinical care. Methods and findings: We did a secondary analysis of cross-sectional, nationally representative, individual-patient data from 187,552 people with hypertension (mean age 48.1 years, 53.5% female) living in 43 low- and middle-income countries (LMICs) and 40,795 people with diabetes (mean age 52.2 years, 57.7% female) living in 28 LMICs on progress through cascades of care (condition diagnosed, treated, or controlled) for diabetes or hypertension, to indicate outcomes of provision of quality clinical care. Data were extracted from national-level World Health Organization (WHO) Stepwise Approach to Surveillance (STEPS), or other similar household surveys, conducted between July 2005 and November 2016. We used mixed-effects logistic regression to estimate associations between each quality clinical care outcome and indicators of country development (gross domestic product [GDP] per capita or Human Development Index [HDI]); national capacity for the prevention and control of noncommunicable diseases (‘NCD readiness indicators’ from surveys done by WHO); health system finance (domestic government expenditure on health [as percentage of GDP], private, and out-of-pocket expenditure on health [both as percentage of current]); and health service readiness (number of physicians, nurses, or hospital beds per 1,000 people) and performance (neonatal mortality rate). All models were adjusted for individual-level predictors including age, sex, and education. In an exploratory analysis, we tested whether national-level data on facility preparedness for diabetes were positively associated with outcomes. Associations were inconsistent between indicators and quality clinical care outcomes. For hypertension, GDP and HDI were both positively associated with each outcome. Of the 33 relationships tested between NCD readiness indicators and outcomes, only two showed a significant positive association: presence of guidelines with being diagnosed (odds ratio [OR], 1.86 [95% CI 1.08–3.21], p = 0.03) and availability of funding with being controlled (OR, 2.26 [95% CI 1.09–4.69], p = 0.03). Hospital beds (OR, 1.14 [95% CI 1.02–1.27], p = 0.02), nurses/midwives (OR, 1.24 [95% CI 1.06–1.44], p = 0.006), and physicians (OR, 1.21 [95% CI 1.11–1.32], p < 0.001) per 1,000 people were positively associated with being diagnosed and, similarly, with being treated; and the number of physicians was additionally associated with being controlled (OR, 1.12 [95% CI 1.01–1.23], p = 0.03). For diabetes, no positive associations were seen between NCD readiness indicators and outcomes. There was no association between country development, health service finance, or health service performance and readiness indicators and any outcome, apart from GDP (OR, 1.70 [95% CI 1.12–2.59], p = 0.01), HDI (OR, 1.21 [95% CI 1.01–1.44], p = 0.04), and number of physicians per 1,000 people (OR, 1.28 [95% CI 1.09–1.51], p = 0.003), which were associated with being diagnosed. Six countries had data on cascades of care and nationwide-level data on facility preparedness. Of the 27 associations tested between facility preparedness indicators and outcomes, the only association that was significant was having metformin available, which was positively associated with treatment (OR, 1.35 [95% CI 1.01–1.81], p = 0.04). The main limitation was use of blood pressure measurement on a single occasion to diagnose hypertension and a single blood glucose measurement to diagnose diabetes. Conclusion: In this study, we observed that indicators of country preparedness to deal with CVDRFs are poor proxies for quality clinical care received by patients for hypertension and diabetes. The major implication is that assessments of countries’ preparedness to manage CVDRFs should not rely on proxies; rather, it should involve direct assessment of quality clinical care.

Despite high cardiovascular mortality in Central Asian republics of the former Soviet Union, there is limited information about major risk factors, including blood lipids. We investigated the prevalence of impaired concentrations of blood lipids, the awareness, treatment and control of hypercholesterolemia, and factors associated with these indicators in urban and rural populations in Kazakhstan. We conducted a cross-sectional study of random urban and rural population samples (the state capital Astana and Akmol village). Men and women aged 50–74 years were examined; a total of 954 adults participated (response rate 59%). Serum concentrations of total, LDL and HDL cholesterol and triglycerides and a range of other cardiovascular risk factors were measured. The overall prevalence of hypercholesterolemia (total cholesterol ≥6.2 mmol/l) was 37%; among subjects with hypercholesterolemia, 57% were aware of their condition, 41% took medication and 23% had total cholesterol <6.2 mmol/l (4.5% <5 mmol/l). The prevalence, awareness, treatment, and control of hypercholesterolemia were all higher in the urban than the rural area. Similarly, the proportions of subjects with impaired concentrations of specific lipids fractions were also considerably higher in the urban population. Most associations with other covariates were in the expected direction. This study found relatively high prevalence of dyslipidemia in the Kazakh population, and the blood lipid profile was less favourable in the urban area. These pronounced urban–rural differences may be related to urbanization, the associated nutrition transition and to access to health care.