Effects of Age, Level of Education and HIV Status on Cognitive Performance in West African Older Adults: The West Africa IeDEA Cohort Collaboration.

An in-depth understanding of the impact of aging, cognitive reserve, and HIV status on cognitive function is needed in older West African adults. Ninety-nine HIV-negative and 334 HIV-positive adults aged ≥ 50 years were enrolled in three clinics (Senegal and Côte d'Ivoire) participating in the IeDEA West Africa collaboration. All subjects underwent the Free and Cued Selective Reminding Test (FCSRT) and the Isaacs Set Test (IST). Age (both linear and quadratic), education level, and HIV status effects on Z-scores were assessed using multivariate linear regression models. Interactions between HIV status and age or educational level were tested. In the present cohort of older West African adults, the role of age and educational level on episodic memory and verbal fluency was observed without revealing an interaction between HIV status and age effect. As age had quadratic effects, older HIV-positive adults should not be considered as a unique group irrespective of their age. Low-educated HIV-positive patients had the lowest verbal fluency performance compared to others. Further studies are needed to duplicate these results. In clinical settings, screening and adapted programs focusing on improving cognition in those patients are needed.

Validation of the D:A:D chronic kidney disease risk score in people living with HIV: the IeDEA West Africa Cohort Collaboration.

OBJECTIVES: A risk score for long-term prediction of chronic kidney disease (CKD) in people living with HIV (PLHIV) has been developed using data from the D:A:D cohort. We assessed the performance of the D:A:D risk score in a cohort of PLHIV in West Africa. METHODS: Data from PLHIV starting antiretroviral treatment in four clinics in Burkina Faso, Côte d'Ivoire and Togo participating in the IeDEA West Africa collaboration were analysed. CKD was defined as two consecutive estimated glomerular filtration rates (eGFRs) of ≤ 60 mL/min/1.73 m2 . The D:A:D score (short version) was calculated using age, gender, nadir CD4 and baseline eGFR and was categorized into low, medium, and high-risk groups. RESULTS: In 14 930 participants (70% female, median age = 38 years; median nadir CD4 count = 183 cells/µL) followed for a median duration of 5.7 years, 660 (4.4%) progressed to CKD, with an incidence [95% confidence interval (CI)] of 7.8 (7.2-8.4) per 1000 person-years (PY). CKD incidence rates were 2.4 (2.0-2.8), 8.1 (6.8-9.6) and, 30.9 (28.0-34.1) per 1000 PY in the low-, medium- and high-risk groups, respectively. In the high-risk group, 14.7% (95% CI: 13.3; 16.3) had progressed to CKD at 5 years. Discrimination was good [C-statistics = 0.81 (0.79-0.83)]. In all, 79.4% of people who progressed to CKD were classified in the medium- to high-risk group at baseline (sensitivity) and 66.5% of people classified in the low risk group at baseline did not progress to CKD (specificity). CONCLUSIONS: These findings confirm the validity of the D:A:D score in identifying individuals at risk of developing CKD who could benefit from enhanced kidney monitoring in West African HIV clinics.

Spreading of SARS-CoV-2 in West Africa and assessment of risk factors.

Although the African continent is, for the moment, less impacted than the rest of the world, it still faces the risk of a spread of COVID-19. In this study, we have conducted a systematic review of the information available in the literature in order to provide an overview of the epidemiological and clinical features of COVID-19 pandemic in West Africa and of the impact of risk factors such as comorbidities, climatic conditions and demography on the pandemic. Burkina Faso is used as a case study to better describe the situation in West Africa. The epidemiological situation of COVID-19 in West Africa is marked by a continuous increase in the numbers of confirmed cases. This geographic area had on 29 July 2020, 131 049 confirmed cases by polymerase chain reaction, 88 305 recoveries and 2102 deaths. Several factors may influence the SARS-CoV-2 circulation in Africa: (i) comorbidities: diabetes mellitus and high blood pressure could lead to an increase in the number of severe cases of SARS-CoV-2; (ii) climatic factors: the high temperatures could be a factor contributing to slow the spread of the virus and (iii) demography: the West Africa population is very young and this could be a factor limiting the occurrence of severe forms of SARS-CoV-2 infection. Although the spread of the SARS-CoV-2 epidemic in West Africa is relatively slow compared to European countries, vigilance must remain. Difficulties in access to diagnostic tests, lack of hospital equipment, but also the large number of people working in the informal sector (such as trading, businesses, transport and restoration) makes it difficult to apply preventive measures, namely physical distancing and containment.

Glycemia and cognitive function in older adults using glucose-lowering drugs.

OBJECTIVES: In experimental studies, both high and low levels of plasma glucose are associated with cognitive impairment. In populations, less is known about the relationship between glycemia and cognitive function, especially in persons using glucose-lowering drugs. DESIGN: A cross-sectional study of 378 high-functioning black and white men and women aged 70 to 79 participating in the Health, Aging, and Body Composition Study (Health ABC) who used glucose-lowering medications. Glycemic measures included fasting plasma glucose (FPG) and glycosylated hemoglobin (HbA1c). Cognitive function was assessed using the Modified Mini-Mental State Examination (3MS) and the Digit Symbol Substitution Test (DSS) at the same examination visit in which the glycemic measures were determined. SETTING: Memphis, Tennessee and Pittsburgh, Pennsylvania. RESULTS: We observed an "inverted-U" relationship (p =.0025 for 3MS, p=.0277 for DSS) between FPG (range 47 - 366 mg/dl) and performance on these two tests. The fasting plasma glucose levels associated with the highest score on the 3MS was 180 mg/dl and 135 mg/dl for the DSS. There was a monotonic inverse relationship between HbA1c and performance on 3MS and DSS without evidence of a threshold effect. CONCLUSION: Our findings suggest that older adults who are treated for diabetes may experience a small degree of cognitive impairment within the recommended fasting glucose levels, yet measures of long-term glycemic control support tight glycemic control. Given the high prevalence of diabetes and the common use of glucose-lowering drugs in older adults, further studies are needed to elucidate these relationships.

Low subcutaneous thigh fat is a risk factor for unfavourable glucose and lipid levels, independently of high abdominal fat. The Health ABC Study.

AIMS: We investigated whether low subcutaneous thigh fat is an independent risk factor for unfavourable glucose and lipid levels, and whether these associations differ between sexes, and between white and black adults. Our secondary aim was to investigate which body composition characteristics (lean tissue, fat tissue) are reflected by anthropometric measures (waist and thigh circumference). METHODS: Anthropometric measurements and computed tomography of the abdomen and of the thigh were performed for all participants of the Health, Aging and Body Composition Study, who were aged 70-79 years. Fasting glucose, triglycerides and HDL-cholesterol, and 2-h postload glucose were determined. RESULTS: After excluding those already diagnosed with diabetes or dyslipidaemia, we analysed data from 2,106 participants. After adjustment for abdominal subcutaneous and visceral fat, and intermuscular thigh fat, larger thigh subcutaneous fat area was statistically significantly associated with lower ln-transformed triglycerides [standardised beta (95% CI) -0.12 (-0.20 to -0.04) in men and -0.13 (-0.21 to -0.05) in women] and higher ln-HDL-cholesterol [0.10 (0.02 to 0.19) and 0.09 (0.01 to 0.18), respectively]. The associations with lower glucose levels were strong in men [-0.11 (-0.20 to -0.02) for fasting and -0.14 (-0.23 to -0.05) for postload glucose], but not statistically significant in women [-0.02 (-0.10 to 0.07) and -0.04 (-0.13 to 0.05), respectively]. There were no differences in the associations between white and black persons. Waist circumference was more strongly associated with abdominal subcutaneous fat, and this association became stronger with increasing BMI, whereas the association with visceral fat became weaker. Thigh circumference was equally dependent on thigh fat and thigh muscle in men, whereas in women the fat component was the main contributor. CONCLUSION: Larger subcutaneous thigh fat is independently associated with more favourable glucose (in men) and lipid levels (in both sexes) after accounting for abdominal fat depots, which are associated with unfavourable glucose and lipid levels. Anthropometric measures reflect different fat depots at different levels of BMI at the abdomen, and reflect both fat and lean tissue at the thigh. These results emphasise the importance of accurate measures of regional body composition when investigating potential health risks.