Increased vitamin B6 turnover is associated with greater mortality risk in the general US population: A prospective biomarker study

Background & aims: Vitamin B6 status and mortality risk are inversely associated in different patient groups, while prospective studies in the general population are lacking. Here, for the first time, we evaluated the association between biomarkers of vitamin B6 status and mortality risk in a large population-based study. Methods: The vitamin B6 vitamers pyridoxal-5'-phosphat (PLP) and 4-pyridoxic acid (4-PA) were measured by high-performance liquid chromatography in the National Health and Nutrition Examination Survey (NHANES) between 2005 and 2010. Participants' vital status and causes of death were recorded until December 2015. Multivariable Cox regression analyses were carried out to estimate Hazard Ratios (HRs) and 95% confidence intervals (CIs) of mortality across quintiles of PLP, 4-PA, and the ratio of 4-PA and PLP. Results: Out of 15,304 study participants aged between 20 and 85 years at baseline, 1666 (7.7%) died during a median follow-up time of 7.8 years. An inverse association between PLP and mortality was found in a multivariable model adjusted for socioeconomic and lifestyle factors but became statistically non-significant upon adjustment for routine biomarkers (C-reactive protein, creatinine, albumin, and alkaline phosphatase). There was a significant linear trend for a positive association between 4-PA levels and mortality risk in the fully adjusted regression model, although a comparison of extreme quintiles (quintile 5 vs. quintile 1) did not show a significant difference (HRQ5vs.Q1 (95% CI): 1.19 (0.93, 1.51), plinear trend = 0.02). A positive association between the 4-PA/PLP ratio and all-cause mortality was observed in the multivariable model, with an HRsQ5vs.Q1 of 1.45 (95% CI: 1.14, 1.85; plinear trend<0.0001). There were no significant associations between the biomarkers and cardiovascular or cancer mortality. The association between 4-PA/PLP and mortality risk was heterogeneous across age groups, and only statistically significant among participants older than 65 years at baseline (HRQ5vs.Q1 (95% CI): 1.72 (1.29, 2.29), plinear trend<0.0001). In this group, 4-PA/PLP was also associated with cancer mortality, with an HR Q5vs.Q1 of 2.16 (1.20, 3.90), plinear trend = 0.02). Conclusion: Increased vitamin B6 turnover, as indicated by a higher 4-PA/PLP ratio, was associated with all-cause and cancer mortality among the older U.S. general population. Intervention trials are needed to assess whether older individuals with a high 4-PA/PLP ratio would benefit from increased vitamin B6 intake. Keywords: 4-Pyridoxic acid; Mortality; Prospective study; Pyridoxal-5′-phosphat; Vitamin B6

Multiplicity of Plasmodium falciparum infection following intermittent preventive treatment in infants

ABSTRACT: BACKGROUND: Intermittent preventive treatment in infants with sulphadoxine-pyrimethamine (IPTi-SP) reduces malaria morbidity by 20% to 33%. Potentially, however, this intervention may compromise the acquisition of immunity, including the tolerance towards multiple infections with Plasmodium falciparum. METHODS: Plasmodium falciparum isolates were obtained from children participating in two Ghanaian IPTi-SP trials (Tamale, Afigya Sekyere) at 15 months of age, i.e., six months after they had received the second dose of IPTi-SP or placebo. By typing the polymorphic merozoite surface protein 1 (msp1) and msp2 genes, multiplicity of infection (MOI) was assessed in 389 isolates. A total of additional 133 samples were collected in Tamale at 3, 6, 9, and 12 months of age. Comparisons of MOI between groups were done by non-parametric statistical tests. RESULTS: The number of distinguishable P. falciparum clones (MOI) ranged between one and six. Mean MOI in Tamale was stable at 2.13 - 2.17 during the first year of life, and increased to 2.57 at age 15 months (P = 0.01). At no age did MOI differ between the IPTi-SP and placebo groups (each, P [greater than or equal to] 0.5). At 15 months of age, i.e., six months after the second dose, MOI was very similar for children who had received IPTi or placebo (means, 2.25 vs. 2.33; P = 0.55) as was the proportion of polyclonal infections (69.6% vs. 69.7%; P = 0.99). Adjusting for study site, current and prior malaria, parasite density, and season did not change this finding. CONCLUSIONS: IPTi-SP appears to have no impact on the multiplicity of infection during infancy and thereafter. This suggests that tolerance of multiple infections, a component of protective immunity in highly endemic areas, is not affected by this interventio

Strategies to Enhance Retention in a Cohort Study Among Adults of Turkish Descent Living in Berlin

Retention is important for statistical power and external validity in long-term cohort studies. The aims of our study were to evaluate different retention strategies within a cohort study of adults of Turkish descent in Berlin, Germany, and to compare participants and non-participants. In 2011-2012, a population-based study was conducted among adults of Turkish descent to primarily examine recruitment strategies. 6 years later, the participants were re-contacted and invited to complete a self-report questionnaire regarding their health status, health care utilization, and satisfaction with medical services. The retention strategy comprised letters in both German and Turkish, phone calls, and home visits (by bilingual staff). We calculated the response rate and retention rate, using definitions of the American Association for Public Opinion Research, as well as the relative retention rate for each level of contact. Associations of baseline recruitment strategy, sociodemographic, migration-related and health-related factors with retention were investigated by logistic regression analysis. Of 557 persons contacted, 249 (44.7%) completed the questionnaire. This was 50.1% of those whose contact information was available. The relative retention rate was lowest for phone calls (8.9%) and highest for home visits (18.4%). Participants were more often non-smokers and German citizens than non-participants. For all remaining factors, no association with retention was found. In this study, among adults of Turkish descent, the retention rate increased considerably with every additional level of contact. Implementation of comprehensive retention strategies provided by culturally matched study personnel may lead to higher validity and statistical power in studies on migrant health issues

The Impact of Rainfall Variability on Diets and Undernutrition of Young Children in Rural Burkina Faso

Background: Climate change and consequent increases in rainfall variability may have negative consequences for the food production of subsistence farmers in West Africa with adverse impacts on nutrition and health. We explored the pathway from rainfall through diet up to child undernutrition for rural Burkina Faso. Methods: The study used data of a dynamic cohort with 1,439 children aged 7-60 months from the Nouna Health and Demographic Surveillance Site (HDSS) for 2017 to 2019. We assessed data on diets, height, weight, household characteristics, and daily precipitation (from 1981 to 2019). Principal component analysis was used to identify distinct child dietary patterns (Dietary Pattern Scores, DPS). These were related to 15 rainfall indicators by area to obtain a precipitation variability score (PVS) through reduced rank regression (RRR). Associations between the PVS and anthropometric measures, height-for-age (HAZ), and weight-for-height (WHZ), were examined using multi-level regression analysis. Results: Stunting (HAZ < -2) and wasting (WHZ < -2) were seen in 24 and 6% of the children. Three main dietary patterns were identified (market-based, vegetable-based, and legume-based diets) and showed mixed evidence for associations with child undernutrition. The RRR-derived PVS explained 14% of the total variance in these DPS. The PVS was characterized by more consecutive dry days during the rainy season, higher cumulative rainfall in July and more extremely wet days. A 1-point increase in the PVS was associated with a reduction of 0.029 (95% CI: -0.06, 0.00, p < 0.05) in HAZ in the unadjusted, and an increase by 0.032 (95% CI: 0.01, 0.06, p < 0.05) in WHZ in the fully adjusted model. Conclusion: Rainfall variability was associated with dietary patterns in young children of a rural population of Burkina Faso. Increased rainfall variability was associated with an increase in chronic undernutrition, but not in acute undernutrition among young children

A cross-sectional study on the co-occurrence of infectious diseases, malnutrition and cardio-metabolic risk factors

In sub-Saharan Africa, infectious diseases and malnutrition constitute the main health problems in children, while adolescents and adults are increasingly facing cardio-metabolic conditions. Among adolescents as the largest population group in this region, we investigated the co-occurrence of infectious diseases, malnutrition and cardio-metabolic risk factors (CRFs), and evaluated demographic, socio-economic and medical risk factors for these entities. In a cross-sectional study among 188 adolescents in rural Ghana, malarial infection, common infectious diseases and Body Mass Index were assessed. We measured ferritin, C-reactive protein, retinol, fasting glucose and blood pressure. Socio-demographic data were documented. We analyzed the proportions (95% confidence interval, CI) and the co-occurrence of infectious diseases (malaria, other common diseases), malnutrition (underweight, stunting, iron deficiency, vitamin A deficiency [VAD]), and CRFs (overweight, obesity, impaired fasting glucose, hypertension). In logistic regression, odds ratios (OR) and 95% CIs were calculated for the associations with socio- demographic factors. In this Ghanaian population (age range, 14.4–15.5 years; males, 50%), the proportions were for infectious diseases 45% (95% CI: 38–52%), for malnutrition 50% (43–57%) and for CRFs 16% (11–21%). Infectious diseases and malnutrition frequently co-existed (28%; 21–34%). Specifically, VAD increased the odds of non-malarial infectious diseases 3-fold (95% CI: 1.03, 10.19). Overlap of CRFs with infectious diseases (6%; 2–9%) or with malnutrition (7%; 3–11%) was also present. Male gender and low socio-economic status increased the odds of infectious diseases and malnutrition, respectively. Malarial infection, chronic malnutrition and VAD remain the predominant health problems among these Ghanaian adolescents. Investigating the relationships with evolving CRFs is warranted

Type 2 Diabetes Mellitus and Increased Risk for Malaria Infection

A case–control study of 1,466 urban adults in Ghana found that patients with type 2 diabetes mellitus had a 46% increased risk for infection with Plasmodium falciparum. Increase in diabetes mellitus prevalence may put more persons at risk for malaria infection

Microvascular and macrovascular complications in type 2 diabetes Ghanaian residents in Ghana and Europe: The RODAM study.

AIMS: To compare microvascular and macrovascular complication rates among Ghanaians with type 2 diabetes (T2D) living in Ghana and in three European cities (Amsterdam, London and Berlin). METHODS: Data from the multicenter Research on Obesity and Diabetes among African Migrants (RODAM) study were analyzed. 650 Ghanaian participants with T2D (206 non-migrant and 444 migrants) were included. Logistic regression analyses were used to determine the association between migrant status and microvascular (nephropathy and retinopathy) and macrovascular (coronary artery disease (CAD), peripheral artery disease (PAD) and stroke) complications with adjustment for age, gender, socioeconomic status, alcohol, smoking, physical activity, hypertension, BMI, total-cholesterol, and HbA1c. RESULTS: Microvascular and macrovascular complications rates were higher in non-migrant Ghanaians than in migrant Ghanaians (nephropathy 32.0% vs. 19.8%; PAD 11.2% vs. 3.4%; CAD 18.4% vs. 8.3%; and stroke 14.5% vs. 5.6%), except for self-reported retinopathy (11.0% vs. 21.6%). Except nephropathy and stroke, the differences persisted after adjustment for the above-mentioned covariates: PAD (OR 7.48; 95% CI, 2.16-25.90); CAD (2.32; 1.09-4.93); and retinopathy (0.23; 0.07-0.75). CONCLUSIONS: Except retinopathy, the rates of microvascular and macrovascular complications were higher in non-migrant than in migrant Ghanaians with T2D. Conventional cardiovascular risk factors did not explain the differences except for nephropathy and stroke

Smoking prevalence differs by location of residence among Ghanaians in Africa and Europe: The RODAM study.

BACKGROUND: Although the prevalence of smoking is low in Ghana, little is known about the effect of migration on smoking. Comparing Ghanaians living in their country of origin to those living in Europe offers an opportunity to investigate smoking by location of residence and the associations between smoking behaviours and migration-related factors. METHODS: Data on a relatively homogenous group of Ghanaians living in London (n = 949), Amsterdam (n = 1400), Berlin (n = 543), rural Ghana (n = 973) and urban Ghana (n = 1400) from the cross-sectional RODAM (Research on Obesity & Diabetes in African Migrants) study were used. Age-standardized prevalence rates of smoking by location of residence and factors associated with smoking among Ghanaian men were estimated using prevalence ratios (PR: 95% CIs). RESULTS: Current smoking was non-existent among women in rural and urban Ghana and London but was 3.2% and 3.3% in women in Amsterdam and Berlin, respectively. Smoking prevalence was higher in men in Europe (7.8%) than in both rural and urban Ghana (4.8%): PR 1.91: 95% CI 1.27, 2.88, adjusted for age, marital status, education and employment. Factors associated with a higher prevalence of smoking among Ghanaian men included European residence, being divorced or widowed, living alone, Islam religion, infrequent attendance at religious services, assimilation (cultural orientation), and low education. CONCLUSION: Ghanaians living in Europe are more likely to smoke than their counterparts in Ghana, suggesting convergence to European populations, although prevalence rates are still far below those in the host populations