Study design, population and setting.
We conducted a retrospective cross-sectional analysis among ALHIV enrolled in a longitudinal cohort study examining CVD disease burden and risks “Ideal Cardiovascular Health: Distribution, Determinants and Relationship with Health Status among People Living with HIV in Urban Tanzania” which has been described elsewhere (18). This study was conducted in six urban public HIV Care and Treatment clinics (CTCs) in Dar es Salaam, Tanzania. Study participants included ALHIV age >18 who were receiving care at these HIV CTCs at least 12 months prior to enrollment. Pregnant women and persons unable to give informed consent were excluded. A total of 629 participants were recruited between November 2020 to January 2021. In this analysis, only participants who were receiving or about to initiate TLD, and those with complete lab results were included (n=389).
Clinical care in HIV CTCs
HIV care and treatment in Tanzania is provided free of charge under the test and treat approach. TLD is the current recommended first-line regimen for ALHIV which became available in Tanzania in 2019 (19). Patients followed at either monthly clinic visits or every six months if stable, are defined as being on ART for at least six months with no adverse drug reactions that require regular monitoring, good adherence, undetectable HIV viral load< 50 copies/ml and no current illness (opportunistic infections) (19).
Medications for hypertension, diabetes and dyslipidemia are provided free of charge when they are available at the facility. Otherwise, patients are given a prescription to procure (out of pocket payment or covered by health insurance) these medications at a nearby pharmacy. The Tanzania HIV National Guidelines (19), recommend all patients should be screened for CVD risk factors including blood pressure (BP), body weight and height for body mass index (BMI) measurement at each clinic visit, and recieve health education on lifestyle modification to reduce CVD risk. If available at the facility, the guidelines also recommend blood glucose, lipids and chemistry testing every three months to annually depending on avaliable resources.
Data collection
Data extracted for this analysis included demographics (age, sex, education level, health insurance and occupation), CVD risk factors data, and HIV clinical data (duration on ART, HIV viral load), collected at the first (entry) study visit, using a structured questionnaire administered by a study clinician. Questionnaires were all translated into Swahili. CVD risk factor data included behavioral characteristics such as physical activity, diet, smoking and alcohol consumption, defined based on the American Heart Association (AHA) standard guideline for ideal cardiovascular health index (CVHI) and categorized as being at ideal (1 point), intermediate (0 point) of poor (0 point)(20). (Table 1)
Definition of Ideal cardiovascular health index (Table1)
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POOR (0)
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INTERMEDIATE (0)
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IDEAL (1)
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Smoking
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Current smoker or have quit ≤12 months ago
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Have quit >12 months ago
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Never smoked
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BMI
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≥30 kg/m2
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25.0–29.9 kg/m2
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<25 kg/m2
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Physical activity
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None
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1–149 min per week of moderate intensity activity and/or 1–74 min per week of vigorous intensity physical activity
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≥150 min per week of moderate intensity activity and/or ≥75 min per week of vigorous intensity physical activity
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Diet*
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None—total servings of fruits and vegetables weekly as the cutoff for ideal intake
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1–20 total servings of fruits and vegetables weekly as the cutoff for ideal intake
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≥20 total servings of fruits and/or vegetables weekly as the cutoff for ideal intake
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The ideal diet was adapted from a standard definition of dietary score. Fruits and vegetable intake were used as proxy for diet score (with >20 total servings of fruits and vegetables weekly as the cutoff for ideal intake)(21).
At the entry study visit, participants also underwent anthropometric measurements including, weight waist circumference, height/weight and blood pressure measurement. Weight was measured using a digital scale (Seca, Germany) to the nearest 0.1 kg, and height by a calibrated stadiometer fixed to the wall (Seca, Germany) to the nearest 0.5 cm. BMI was then calculated as weight in kilogram divided by the square if height in metres . A flexible tape measure was used to measure waist circumference (WC) at the level of the iliac crest to the nearest 0.5 cm. Blood pressure (BP) was measured in mmHg to the nearest 1mmHg using a digital sphygmomanometer (Omron). Three BP readings were collected after ensuring the participant was seated in a comfortable position with their arm at the level of the heart. An average of the three readings was computed and considered final. Participants also had blood collected for fasting blood glucose levels, measured using a capillary finger prick test. A standardized automated point of care analyzer (ACCU-CHEK Performa, Roche, Germany) was used. Venous blood was collected to assess the lipid profile including total cholesterol, high density lipoprotein (HDL), low densitiy lipoprotein (LDL) and triglycerides, analyzed using Cobas 400 analyzer (Roche Diagnostics).
Outcomes
The primary outcome in this study was the prevalence of MetS among ALHIV. MetS was defined according to the NCEP ATP III definition, as present if there were >3 of the following five criteria: waist circumference over 40 inches (men) or 35 inches (women), BP> 130/85 mmHg, fasting triglyceride (TG) level >150 mg/dl, fasting high-density lipoprotein (HDL) cholesterol level < 40 mg/dl (men) or 50 mg/dl (women) and fasting blood sugar > 100 mg/dl (22).
The NCEP ATP III definition is one of the most widely used criteria of MetS. It incorporates key features of hyperglycemia/insulin resistance, visceral obesity, atherogenic dyslipidemia and hypertension. It uses measurements and laboratory results that are readily available to healthcare providers, hence facilitating its clinical and epidemiological application (23) .
Ethical approval
The primary study received ethical clearance from Muhimbili University of Health and Allied Sciences (MUHAS) -MUHAS-REC-01-2023-1500 in Tanzania and Northwestern University, Chicago (STU00218902).
Statistical methods
Data analysis was conducted using STATA version 16 (STATA Corp Inc., TX, USA). Chi-Square test (Fisher’s exact test) and student t-test were used to compare demographic characteristics by sex. Logistic regression was used to determine the association between MetS and covariates; age, sex, education level, occupation, insurance status, smoking status, alcohol drinking, physical activity, diet, BMI, duration on ART and HIV viral load. Co-variates with effect sizes were significant at P < 0.2 were included in multiple logistic regression models. The odds ratio (OR) was presented with 95% CI and P < 0.05 considered significant.