Vitamin A: potential misclassification of vitamin A status among patients with type 2 diabetes and hypertension in urban Ghana

Blood retinol and retinol-binding protein concentrations are associated with diabetes: a systematic review and meta-analysis of observational studies

PURPOSE

The associations between blood retinol, retinol-binding protein (RBP) concentrations and diabetes mellitus were inconsistent in literature. The objective is to investigate these associations by a systematic review and meta-analysis and provide basis for clinical intervention.

METHODS

PubMed, Web of science, and Cochrane databases were searched from the beginning to July 1, 2021. A total of 13 studies on retinol and 31 studies on RBP are included in the current meta-analysis.

RESULTS

The blood retinol concentration was significantly lower in the type I diabetes mellitus (T1DM) [standardized mean difference (SMD) (95% CI): - 0.59 (- 0.81, - 0.37), P < 0.01] and gestational diabetes mellitus (GDM) patients [SMD (95% CI): - 0.54 (- 0.87, - 0.20), P < 0.01] than in the controls. However, the difference was not significant between the type II diabetes mellitus (T2DM) patients and the controls. The RBP concentration was significantly higher in the diabetic patients than in the controls [SMD (95% CI): 0.24 (0.12, 0.35), P < 0.01]. Particularly, the RBP concentration was significantly higher in the T2DM and GDM patients.

CONCLUSION

The blood retinol concentration was negatively associated with T1DM and GDM, while the blood RBP concentration was positively associated with T2DM and GDM. Future work should use a more sensitive retinol measurement method like retinol isotope dilution method to confirm whether blood retinol concentration differs between the diabetes patients and the controls.

Increased Blood Retinol Levels Are Associated With a Reduced Risk of TIA or Stroke in an Adult Population: Lifestyle Factors- and CVDs-Stratified Analysis

Background: Data on the existing evidence for the association between blood retinol and transient ischemic attack (TIA)/stroke risk are limited, and the results are inconclusive. This study aimed to further assess the associations between the blood retinol levels and the risk of TIA/stroke after controlling the lifestyle factors and age-related confounders. Methods: The cross-sectional data from 1,113 individuals (aged 34-84 years old) were obtained from the Midlife in the United States (MIDUS) study. The multivariable analyses were performed to investigate the association of blood retinol levels with ever and currently TIA/stroke. Results: There was an inverse association between the blood retinol levels and the risk of ever TIA or stroke (for per 1 μmol/L adjusted odds ration [OR]: 0.93; 95% CI: 0.89-0.97; for per 1-SD adjusted OR: 0.89; 95% CI: 0.83-0.96) and currently diagnosed TIA or stroke (for per 1 μmol/L adjusted OR: 0.91; 95% CI: 0.87-0.96; for per 1-SD adjusted OR: 0.84; 95% CI: 0.80-0.91) after controlling the lifestyle factors and age-related confounders. The significance of these associations was maintained after a sensitivity analysis and involving "ever chronic respiratory diseases" as a covariate. Moreover, the stratified analyses suggested that the inverse associations could be affected by overweight [body mass index (BMI) ≥ 28, kg/m²], hypertension, and diabetes. Conclusions: A significant inverse association between blood retinol and the risk of TIA or stroke was found. This inverse association did not change even after adjustment for many potential confounders. Moreover, the potential protective effect of retinol on TIA/stroke could be blunted by overweight [BMI ≥ 28, kg/m²], hypertension, and diabetes.

The Double Burden of Malnutrition at the Individual Level Among Adults: A Nationwide Survey in the Philippines

Introduction: Double burden of malnutrition (DBM) is a fast-evolving public health challenge. The rising prevalence of obesity and diet-related non-communicable diseases alongside persistent nutritional deficiencies are compelling problems in many developing countries. However, there is limited evidence on the coexistence of these conditions in the same individual among community-dwelling adults. This cross-sectional study describes the various forms of DBM and examines the determinants of DBM at the individual level among adults in the Philippines. Materials and Methods: A nationwide dataset from the 2013 Philippine National Nutrition Survey was used. The final study sample consisted of 17,157 adults (8,596 men and 8,561 non-pregnant and non-lactating women). This study focused on three DBM types within adults: (#1) Underweight and at least one cardiometabolic risk factor (Uw + ≥1 CMRF), (#2) Anemia and at least one cardiometabolic risk factor (An + ≥1 CMRF), (#3) Vitamin A deficiency or iodine insufficiency and at least one cardiometabolic risk factor (Other MND + ≥1 CMRF). The total double burden of malnutrition was also evaluated as the sum of the aforementioned three types. Logistic regression models were used to assess associations between socio-demographic and lifestyle factors and DBM. Results: The prevalence of the three types of DBM were: type #1, 8.1%; type #2, 5.6%; type #3, 20.6%, and the total DBM prevalence was 29.4%. Sex, age, educational attainment, employment status, wealth quintile, and alcohol drinking were the risk factors for DBM. In contrast, marital status, smoking, and physical activity were associated with the different DBM types. Conclusion: The study findings contribute to the current state of knowledge on the broad spectrum of individual-level DBM. Understanding the disparities of this phenomenon could guide integrated actions directed to the concomitance of malnutrition in various forms and cardiometabolic disease risks.

Adjunctive vitamin A and D for the glycaemic control in patients with concurrent type 2 diabetes and tuberculosis: a randomised controlled trial

The objective of this study is to investigate the effects of vitamin A, D and their interaction on the glycaemic control in patients with both diabetes and tuberculosis. Tuberculosis infection and its treatment induce hyperglycaemia and complicate the glycaemic control in patients with diabetes. A randomised controlled trial with a 2 × 2 factorial design was conducted in a tuberculosis-specialised hospital in Qingdao, China. A total of 279 patients who have both diabetes and tuberculosis were included in this analysis. The patients received standard anti-tuberculosis treatment alone (control group), or together with a dose of vitamin A (600 μg RAE/d) or vitamin D (10 μg/d) or a combination of vitamin A (600 μg RAE/d) and vitamin D (10 μg/d) for 2 months. The effects of the intervention on fasting plasma glucose and 2-h postprandial blood glucose were investigated by ANCOVA. The analysis was adjusted for baseline values, age, sex, smoking, drinking and antidiabetic treatment as covariates. No significant effect was observed for vitamin A and D supplementation on fasting plasma glucose, 2-h postprandial blood glucose, BMI and related blood parameters. No interaction was observed between vitamin A and D supplementation for these endpoints. Vitamin A and D supplementation showed a null effect on the glycaemic control for patients with concurrent diabetes and tuberculosis. Future work should evaluate the effect of vitamin A and D supplementation on insulin-related indices for these patients and investigate the effect of vitamin D receptor genotypes.

Medication Intake Is Associated with Lower Plasma Carotenoids and Higher Fat-Soluble Vitamins in the Cross-Sectional MARK-AGE Study in Older Individuals

The regular use of medication may interfere with micronutrient metabolism on several levels, such as absorption, turnover rate, and tissue distribution, and this might be amplified during aging. This study evaluates the impact of self-reported medication intake on plasma micronutrients in the MARK-AGE Project, a cross-sectional observational study in 2217 subjects (age- and sex-stratified) aged 35-75 years from six European countries that were grouped according to age. Polypharmacy as possible determinant of micronutrient concentrations was assessed using multiple linear regression models adjusted for age-group, dietary fruit, vegetables, and juice intake, and other confounders. Younger participants reported taking fewer drugs than older participants. Inverse associations between medication intake and lutein (-3.31% difference per increase in medication group), β-carotene (-11.44%), α-carotene (-8.50%) and positive associations with retinol (+2.26%), α-tocopherol/cholesterol (+2.89%) and γ-tocopherol/cholesterol (+1.36%) occurred in multiple adjusted regression models. Combined usage of a higher number of medical drugs was associated with poorer status of carotenoids on the one hand and higher plasma concentrations of retinol, α- and γ-tocopherol on the other hand. Our results raise concerns regarding the safety of drug combinations via the significant and surprisingly multifaceted disturbance of the concentrations of relevant micronutrients.

Dietary and Health Characteristics of Korean Adults According to the Level of Energy Intake from Carbohydrate: Analysis of the 7th (2016-2017) Korea National Health and Nutrition Examination Survey Data

The purpose of this study was to examine the association between the level of energy intake from carbohydrate and the dietary and health characteristics among Korean adults. We examined the diet quality and health conditions of Korean adults by segmenting them into eight groups according to the level of energy intake from carbohydrate (<45%, 45–50%, 50–55%, 55–60%, 60–65%, 65–70%, 70–75%, and ≥75%). From the data of the 7th (2016–2017) Korea National Health and Nutrition Examination Survey (KNHANES), 7566 subjects aged 19 to 64 years were analyzed. Diet quality was much lower in the groups whose energy intake from carbohydrate was <50% or ≥65%, compared to the groups whose energy intake from carbohydrate was 50–65%. Hypertension or low HDL-cholesterolemia was associated with low (<45%) or high (≥70%) energy intake from carbohydrate. We found no considerable difference in the diet quality and health conditions between the groups whose energy intake from carbohydrate was 50–55% and 55–65%. In conclusion, it is suggested to expand the current acceptable macronutrient distribution range (AMDR) for carbohydrate for Korean adults (i.e., 55% to 65%) to include 50–55%.

Creatinine, total cysteine and uric acid are associated with serum retinol in patients with cardiovascular disease

Purpose

We hypothesized that biomarkers and dietary factors related to cardiovascular disease risk were associated with serum retinol and evaluated these potential associations in patients with suspected coronary artery disease (CAD).

Methods

We used cross-sectional data from 4116 patients hospitalised for suspected CAD. Dietary data were obtained from a subgroup of 1962 patients using a food frequency questionnaire. Potential biomarkers and dietary factors were explored using linear regression modelling adjusted for age and sex. Regression coefficients and corresponding confidence intervals (CI) are given as  % change in serum retinol per unit change in the predictors. Analyses were performed in the total population and in strata of serum retinol tertiles.

Results

In age- and sex-adjusted models, serum creatinine (standardized β: 0.38, 95% CI [0.35, 0.42]), plasma total cysteine (0.26, [0.23, 0.29]), serum uric acid (0.30, [0.26, 0.33]) and plasma neopterin (0.22, [0.18, 0.25]) were positively associated, whereas plasma serine (− 0.15, [− 0.18, − 0.12]) and serum C-reactive protein (− 0.15, [− 0.18, − 0.12]) were inversely associated with serum retinol. When we included the significant biomarkers in a multivariate model, the model explained 33% of the variability (R² = 0.33) in serum retinol. The results were similar in the lower and upper tertiles of serum retinol. Weak or no associations were observed for dietary factors.

Conclusions

In patients with suspected CAD, concentrations of creatinine, cysteine and uric acid were positively associated with serum retinol. Future studies should assess whether retinol concentrations are influenced by metabolic alterations in patients at risk of cardiovascular disease.

Correlation between the levels of serum cystatin C and substance P in peripheral blood in diabetes mellitus patients complicated with hypertension

Correlation between the serum cystatin C and substance P in peripheral blood of diabetes mellitus patients complicated with hypertension was investigated. Diabetes mellitus patients with or without hypertension were selected in No. 215 Hospital of Shaanxi Nuclear Industry from December 2015 to February 2017. There were 60 patients with only hypertension (hypertension control group), 60 patients with only diabetes mellitus (diabetes mellitus control group) and 60 patients with diabetes mellitus combined with hypertension (observation group). Levels of serum cystatin C and substance P in peripheral blood were measured via immunoturbidimetry and enzyme-linked immunosorbent assay, respectively, and the correlation with hypertension was analyzed. The average level of serum cystatin C in the observation group was higher than that of the two control groups (P<0.05). The level of substance P in peripheral blood of the observation group was lower than that of the diabetic control group (P<0.05). The levels of serum cystatin C in patients with grade III hypertension in observation group were higher than those in grades II and I, and the levels of substance P in peripheral blood of patients with grade III hypertension in observation group were lower than those in grades II and I. Systolic pressure of patients in observation group was significantly positively correlated with level of serum cystatin C, but significantly negatively correlated with level of substance P in peripheral blood (P<0.05). Compared with the diabetes mellitus patients, level of serum cystatin C was higher, and level of substance P peripheral blood was lower in diabetes mellitus patients complicated with hypertension. In diabetes mellitus patients, blood pressure was positively correlated with serum cystatin C level, and negatively correlated with substance P level in peripheral blood.

Adolescent health in rural Ghana: 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.