In a sunny corner of the Colorado Convention Centre, Johannesburg, clinician-scientist Dr Nomathemba Chandiwana talks about how she’s been up since 5am doing interviews with media back in South Africa for World Obesity Day on 4 March. Outside the convention centre on the horizon, the snow-capped Rocky Mountains sprawl.

Chandiwana refers to obesity as a public health crisis in South Africa, similar to HIV in the late 1990s. 

She advocates semaglutide (sold under the brand name Ozempic) and similar medicines to be rolled out countrywide. (Spotlight previously published an in-depth feature on the case for using breakthrough new weight loss medicines in South Africa.)

In many countries, semaglutide injections are prescribed for treating type 2 diabetes, but more recently also for weight loss – by those who can afford the hefty price tag. 

Its use by people living with HIV to induce weight loss was the subject of several studies presented at the Conference on Retroviruses and Opportunistic Infections (CROI) hosted in Denver, Colorado, this year.

Inside the convention centre, Chandiwana waves at familiar delegates, greeting people with a hug. A medical doctor and convener of large-scale HIV clinical trials, her research has lately converged on obesity and HIV and resulting complications such as liver fat, cardiometabolic health, type 2 diabetes and obstructive sleep apnoea.

“We’re using HIV as a blueprint for the obesity epidemic because it’s South Africa’s biggest public health success. With HIV, initially, the drugs were too expensive as well, but people fought and things changed,” Chandiwana says.

In South Africa, semaglutide costs around R6,000 a month. It is registered for treating type 2 diabetes only, and there are widespread supply shortages. 

Chandiwana says that, similar to antiretrovirals, generic equivalents of semaglutide and related medicines need to be mass-procured and made available to people suffering from clinical obesity.

Commenting on the drug’s shortages, she says: “It really shows the interest and also the desperation of people to have a medication that works. So people want to be slimmer for a lot of reasons – maybe cosmetic, but also due to impaired body functioning when you are extremely overweight.”

At the conference, Chandiwana presented research that investigated dolutegravir-based antiretroviral therapy, diet, activity and weight gain in 500 people living with HIV. 

The study found that lifestyle behaviour changes had a limited effect on reversing weight gain in this group, concluding that “pharmacological interventions to mitigate clinical obesity in this population may be needed”.

Also at the CROI, Chandiwana was inside a packed auditorium attending a session on semaglutide entitled, “Is the Weight Over? GLP-1 Receptor Antagonists Are Here.” In the talk, scientists presented findings from a study of 222 people suggesting the drug works just as well to reduce weight in people living with HIV, as in people who do not have HIV.

“Among PWH [people living with HIV], semaglutide was associated with significant weight loss, with more substantial weight loss observed in individuals with higher BMI. These findings are highly relevant given the high proportions of diabetes, overweight and obesity among PWH,” the researchers concluded.

Another study presented at the conference examined changes in muscle quality and function among 46 people living with HIV who were treated with semaglutide, noting a loss in muscle mass but not necessarily a loss in muscle quality. 

Findings were also presented on 49 individuals suggesting that low-dose semaglutide is a safe and effective treatment for a form of liver disease that is common in people living with HIV. 

These were both relatively small studies and more research will be required to confirm the findings.

Dr Nomathemba Chandiwana at the Conference on Retroviruses and Opportunistic Infections. (Photo: Biénne Huisman / Spotlight)

A two-tier strategy

For World Obesity Day, Chandiwana co-penned two editorials – one published on Bhekisisa, the other in the South African Medical Journal – stating that about two-thirds of women and almost a third of men in South Africa are overweight.

“Obesity should not be a game of blame and shame,” she writes, along with co-author Prof Francois Venter. 

“Instead, the country’s focus should be on both preventing and treating people.”

In the Bhekisisa article, Chandiwana and Venter put forward a two-tier strategy for combating obesity: first, “trust the science – and make the meds cheaper,” and second, “fix the food system, to support healthy eating and more physical activity.”

However, unequal access to healthy food and safe places to exercise remain a challenge – “for example, ubiquitous, cheap, highly and ultra-processed food and sugar-sweetened beverages offered in slick venues and spaza shops, accompanied by marketing campaigns often aimed at children.”

Chandiwana tells Spotlight that we live in an obesogenic environment. 

“Everything around us is priming us to gain weight,” she says. 

“I mean, with load shedding, what are you going to do? You might just order whatever you can on Uber Eats. Then, as a woman, do you feel safe exercising on your street?” 

She compares this to tobacco lobbying.

“So if you have a child eating McDonald’s at five years old, McDonald’s has a customer for life. It was the same with smoking, right? If you have a teenager smoking, you have a customer for life.”

She says people need help through systematic change brought by government and regulatory interventions. Last year, Spotlight reported on the South African government’s strategy to combat obesity.

Chandiwana helped to write the chapter on HIV treatment in the National Strategic Plan for HIV, TB and STIs 2023-2028, and contributed to treatment guidelines on tuberculosis and sexually transmitted infections such as syphilis.

In September last year, along with South African sleep disorder specialist Dr Alison Bentley, Chandiwana co-founded a pioneering sleep clinic at the Ezintsha research centre in Parktown. 

Chandiwana, the principal scientist and director at Ezintsha, says: “Dr Bentley has been amazing and taught me a lot. She does the clinical aspects of [the sleep clinic] and I do the research … Sleep is about so much more than just having a mattress – it’s about your health.”

Currently, they are monitoring up to a hundred women living with HIV for sleep apnoea, Chandiwana says. These women stay overnight for polysomnography testing, which records brain waves, blood oxygen levels, heart rate and breathing during sleep. It also measures eye and leg movements.

African solutions for African problems

The idea of finding African solutions for African problems is close to Chandiwana’s heart. 

“Having an African-led research agenda is really important, I think. You look at a conference like the CROI and most of the stuff that’s being done in HIV is actually on the African continent. But it’s not Africans talking about the issues we have.” 

To this end, she mentions the annual INTEREST Conference – marketed as the premier scientific conference for HIV in Africa – which she plans on attending in Benin in May.

Born to epidemiologist Prof Stephen Chandiwana from Zimbabwe – later assistant dean at Wits University’s faculty of health sciences – and Duduzile from Swaziland who worked for UNAids, Chandiwana was the middle child of three siblings. 

Initially, because of her father’s medical background, she rebelled against becoming a doctor.

“I always tell people I took the scenic route to medical school.”

After completing a Bachelor of Science in behavioural neuroscience at Northeast University in Boston, and working for a year at a sugar refinery in London, she finally enrolled for medical school at Wits University.

Chandiwana’s husband, Zviko Mudimu, works for the South African National Space Agency and is looking after their son (4) and daughter (7) while she is in Denver attending the CROI. 

At their home in Parktown West, she enjoys gardening and growing vegetables like spinach and eggplant.

Wrapping up our interview, as the next conference session is about to start, Chandiwana stresses the importance of science made accessible to a wider audience: 

“As scientists – and I’m guilty of it – we speak to each other, we speak to the choir. And I’ve had to learn this … we need to be able to communicate on broader platforms. Because in the end, it’s only your mom and your colleagues that read your [academic] papers, right?” She pauses with a laugh. 

“My mom still prints out my papers. Isn’t that sweet?”

She adds: “So even things like speaking on the radio are important because if you don’t, [public discourse] becomes filled with other people saying other things. For example, that diet and exercise are the only way forward, and that people who have obesity are lazy. 

“So you need to be on those platforms too, speaking evidence-based truths but in accessible short bites that people can grasp.” DM

This article was published by Spotlight – health journalism in the public interest. Sign up to the Spotlight newsletter.