Title: Prevalence and Determinants of Hypertension Among People Living with HIV on Antiretroviral Therapy: A Cross-Sectional Study at Mwananyamala Hospital, Tanzania.

This cross-sectional study at Mwananyamala Hospital in Tanzania reveals a 32.8% prevalence of hypertension among people living with HIV on antiretroviral therapy, identifying older age, cigarette smoking, and longer duration since HIV diagnosis as significant risk factors while highlighting the need for integrated screening and education to address this growing comorbidity.

The Gist

Imagine your body as a busy city. For a long time, the main problem in this city was a sudden, violent storm called HIV. But thanks to modern medicine (antiretroviral therapy, or ART), the storm has been tamed. The city is now safe, and the people living there are living longer, healthier lives.

However, as the city has grown older and more stable, a new, quieter problem has started to creep in: Hypertension (high blood pressure). Think of this not as a storm, but as the city's water pipes slowly getting clogged and the pressure building up inside them. If you don't check the pressure, the pipes can burst, leading to heart attacks or strokes.

This study, conducted at a major hospital in Dar es Salaam, Tanzania, went into this "city" to see how many people were dealing with these clogged pipes and what was causing the pressure to rise.

The Big Picture: What They Found

The researchers looked at 296 people living with HIV who had been on their medication for at least six months.

• The Prevalence (How common is it?): They found that about 1 in 3 people (32.8%) had high blood pressure.
  • The Analogy: If you walked into a room with 30 people living with HIV, about 10 of them would likely have high blood pressure. This is significantly higher than the general population in Tanzania, where only about 1 in 10 adults has it.
• The Knowledge Gap: The researchers asked these people, "Do you know what high blood pressure is?"
  • The Analogy: Imagine a driver's test. Most people knew the basics (like "don't smoke" or "exercise"), but when asked, "What is the actual speed limit (normal blood pressure number)?" only 10% got it right. It's like knowing you shouldn't drive too fast, but not knowing what the speed limit actually is.

The "Culprits": What Makes the Pressure Rise?

The study tried to figure out why the pressure was high. They looked at two types of suspects: Traditional Suspects (things that affect everyone) and HIV-Specific Suspects (things related to the virus or its treatment).

1. The Traditional Suspects (The Usual Suspects)

• Age: The older you get, the higher the pressure.
  • The Metaphor: Think of your blood vessels like garden hoses. Over time, hoses get stiff and less flexible. People aged 55 and older were almost 5 times more likely to have high blood pressure than younger people.
• Smoking: This was a huge factor.
  • The Metaphor: Smoking is like pouring sand into your garden hose. It damages the inside and makes the pressure spike. Smokers in the study were 6 times more likely to have high blood pressure.
• Weight: Interestingly, in this specific study, being overweight didn't show a strong link after adjusting for other factors, though it is usually a risk.

2. The HIV-Specific Suspects (The Unique Factors)

• Time with the Virus: The longer someone has lived with HIV (more than 10 years), the higher the risk.
  • The Metaphor: Even though the virus is controlled, it's like a slow leak in the city's foundation. Years of chronic inflammation (the body's constant "fight or flight" mode) wear down the pipes over time.
• Time on Medication: People who had been on ART for less than 5 years actually had a lower risk.
  • The Metaphor: This suggests that the "wear and tear" of long-term treatment, combined with aging, adds up. It's like a car that runs perfectly for the first few years, but after a decade, the engine needs more maintenance to keep running smoothly.

What Does This Mean for the Future?

The study concludes that while HIV is no longer a death sentence, it has turned into a chronic condition that requires a different kind of care.

• The Problem: HIV clinics are great at treating the virus, but they aren't always checking the "water pressure" (blood pressure).
• The Solution: We need to integrate the two. Just as you check your oil when you get an oil change, HIV clinics should check blood pressure at every visit.
• Education: We need to teach patients not just that they have high blood pressure, but what the numbers mean and how to fix it (stop smoking, eat better, move more).

The Bottom Line

Living with HIV today is like living in a city that has survived a war but is now facing the challenges of aging infrastructure. The war (HIV) is under control, but the pipes (blood vessels) are getting old and clogged. By checking the pressure, fixing the leaks (smoking), and maintaining the infrastructure (lifestyle changes), we can ensure these cities remain vibrant and safe for a long time to come.

Technical Summary

1. Problem Statement

As life expectancy for People Living with HIV (PLHIV) improves due to the scale-up of Antiretroviral Therapy (ART), the morbidity profile has shifted from opportunistic infections to non-communicable diseases (NCDs), particularly hypertension. While hypertension is a known comorbidity in PLHIV, there is a lack of consistent evidence regarding its prevalence and specific determinants in Tanzania. Existing literature presents conflicting data on whether HIV-specific factors (e.g., CD4 count, duration of infection, ART duration) or traditional risk factors (e.g., age, BMI, lifestyle) are the primary drivers. Furthermore, there is a gap in understanding hypertension knowledge levels among this population, which hinders effective prevention and management. This study aims to fill these gaps by assessing the prevalence, associated factors, and knowledge levels of hypertension among PLHIV on ART in an urban Tanzanian setting.

2. Methodology

• Study Design & Setting: A hospital-based cross-sectional study conducted at Mwananyamala Regional Referral Hospital (MRRH) in Dar es Salaam, Tanzania, between September 2024 and March 2025.
• Population: 296 PLHIV (aged ≥18 years) who had been on ART for more than six months. Pregnant women and those on contraceptive pills were excluded to avoid blood pressure confounding.
• Sampling: Simple random sampling was used to select 329 potential participants from daily clinic lists; 296 completed the study (response rate ~90%).
• Data Collection:
  • Questionnaires: Structured interviews in Swahili collected sociodemographic data, lifestyle factors (smoking, alcohol, physical activity), and hypertension knowledge (using a modified 10-item Hypertension Knowledge-Level Scale).
  • Clinical Measurements: Blood pressure was measured twice by registered nurses following American Heart Association (AHA) guidelines. Hypertension was defined as ≥140/90 mmHg or current use of antihypertensive medication.
  • Anthropometry: Height and weight were measured to calculate BMI.
  • Records: HIV-specific data (CD4 count, WHO stage, duration of diagnosis, ART duration) were extracted from Care and Treatment Clinic (CTC) records.
• Statistical Analysis: Data were analyzed using SPSS 26. Descriptive statistics summarized characteristics. Bivariate and multivariate logistic regression models were used to identify independent predictors of hypertension, with statistical significance set at p < 0.05.

3. Key Contributions

• Contextual Evidence: Provides updated, site-specific data on the dual burden of HIV and hypertension in Tanzania, a region where NCDs are increasingly prevalent among PLHIV.
• Differentiation of Risk Factors: Explicitly separates traditional risk factors from HIV-specific clinical markers (CD4 count, HIV staging, ART duration) to determine their independent contributions to hypertension risk.
• Knowledge Assessment: Utilizes a structured, validated tool to quantify hypertension knowledge, revealing specific gaps (e.g., low awareness of normal blood pressure thresholds) that can inform targeted health education.
• Methodological Rigor: Adheres to AHA guidelines for BP measurement and employs multivariate analysis to control for confounders, offering a robust estimate of adjusted odds ratios (aOR).

4. Key Results

• Prevalence: The overall prevalence of hypertension was 32.8%, significantly higher than the 11% reported in the general Tanzanian adult population and the global average of 23.6% for PLHIV.
• Knowledge Levels: Overall hypertension knowledge was moderate (mean score 53.9%).
  • Only 10.8% correctly identified normal blood pressure levels.
  • Awareness of complications (e.g., heart problems) was higher (68.6%) than knowledge of risk factors like smoking (22.6%).
• Determinants of Hypertension (Multivariate Analysis):
  • Age: Participants aged ≥55 years had a significantly higher risk of hypertension (aOR = 4.786, p < 0.001).
  • Smoking: Cigarette smoking was a strong independent predictor (aOR = 6.159, p = 0.020).
  • HIV Duration: Living with HIV for >10 years was associated with increased odds (aOR = 3.090, p = 0.011).
  • ART Duration: Paradoxically, shorter ART duration (<5 years) was associated with a lower risk (aOR = 0.106, p = 0.040), suggesting that longer exposure to ART or the cumulative effect of chronic infection increases risk.
  • Non-Significant Factors: Gender, family history, alcohol use, BMI, physical activity, CD4 count, and WHO clinical stage were not statistically significant predictors in the multivariate model.

5. Significance and Implications

• Public Health Burden: The study confirms that hypertension is a major comorbidity affecting nearly one-third of PLHIV in urban Tanzania, necessitating a shift in HIV care models to include routine NCD screening.
• Epidemiological Transition: The findings suggest that as PLHIV age, their cardiovascular risk profile increasingly resembles that of the general ageing population, driven by traditional risk accumulation (age, smoking) and prolonged survival rather than HIV-specific biological mechanisms alone.
• Clinical Recommendations:
  • Integrated Care: Hypertension screening and management must be integrated into routine HIV care services.
  • Targeted Interventions: Special attention should be given to patients aged ≥55 and smokers. Smoking cessation counseling is critical.
  • Education: There is an urgent need to improve patient education regarding normal blood pressure values and behavioral risk factors, as current knowledge levels are insufficient for effective self-management.
• Policy: The study supports the implementation of community engagement strategies for chronic disease screening to reduce the dual burden of HIV and NCDs in Tanzania.

Limitations: The cross-sectional design precludes causal inference, and specific ART regimens were not analyzed, which limits the ability to attribute hypertension to specific drug classes.