Weight Loss with Transthyretin Amyloidosis (ATTR) in South Africa

Transthyretin Amyloidosis (ATTR) is an underdiagnosed systemic disease where a normally harmless protein — transthyretin (TTR), produced by the liver — misfolds and deposits as amyloid fibrils in organs throughout the body, most critically the heart and peripheral nerves. If you've been diagnosed with ATTR, weight management takes on a different meaning: the goal is less about losing dramatic amounts of weight and more about protecting your heart, preserving nutrition, and stopping disease progression. Here's what you need to know in the South African context.

What Is ATTR Amyloidosis?

Transthyretin is a transport protein that normally carries thyroid hormone and vitamin A (retinol) in the bloodstream. In ATTR amyloidosis, TTR protein misfolds and aggregates into insoluble amyloid fibrils that deposit in tissues.

There are two forms:

• Hereditary ATTR (ATTRv): Caused by a variant (mutation) in the TTR gene. Hundreds of pathogenic variants exist worldwide. The most clinically important in sub-Saharan Africa is Val122Ile (p.Val142Ile in updated nomenclature) — carried by approximately 3–4% of people of West African ancestry, making it the most common hereditary amyloidosis variant in the world by carrier frequency. If you are Black African and have cardiac amyloidosis, this variant must be tested for.
• Wild-type ATTR (ATTRwt): No TTR gene mutation — the normal protein misfolds with age. Predominantly affects men over 65. Formerly called "senile cardiac amyloidosis." Increasingly recognised as a major cause of heart failure in older adults.

Target organs and manifestations:

• Heart: Hypertrophic-appearing cardiomyopathy with diastolic dysfunction, thickened walls, heart failure, arrhythmias, conduction disease
• Peripheral nerves: Length-dependent sensorimotor neuropathy (numbness, tingling, weakness in feet and hands); autonomic neuropathy (postural hypotension, diarrhoea, constipation, bladder dysfunction, impotence)
• GI tract: Dysmotility, nausea, early satiety, diarrhoea alternating with constipation, malabsorption — all driving weight loss and malnutrition
• Kidneys: Proteinuria, progressive renal impairment
• Eyes: Vitreous opacities (a clinical clue to hereditary ATTR)
• Carpal tunnel syndrome: Often an early manifestation, years before cardiac disease

In South Africa, ATTR diagnosis requires a high index of suspicion. Echo findings of cardiac amyloid should prompt 99mTc-DPD bone scintigraphy (nuclear medicine scan — available at academic hospitals) and TTR gene sequencing via NHLS. Early diagnosis now matters enormously because disease-modifying therapies exist.

The Weight Issue in ATTR: It's Not What You Think

Unlike most conditions on this website, in ATTR amyloidosis the primary weight concern is often preventing weight loss, not losing it. Here's why:

• GI amyloid infiltration causes malabsorption, early satiety, nausea, and diarrhoea — patients often lose significant weight even without trying
• Cardiac cachexia — advanced heart failure drives a catabolic state where the body breaks down muscle and fat regardless of intake
• Autonomic neuropathy causes orthostatic hypotension (dizziness on standing), which discourages eating and physical activity
• Early satiety from GI dysmotility means patients cannot eat large volumes

However: If you are overweight or obese AND have ATTR, reducing excess weight is genuinely beneficial — it reduces cardiac preload and afterload, improving heart failure symptoms. The key is doing so gradually and safely, not aggressively, and maintaining muscle mass throughout.

Red flag: If you are losing weight unintentionally with ATTR, this must be reported to your cardiologist and gastroenterologist urgently — it signals disease progression, not progress.

Exercise with ATTR Amyloidosis: Proceed with Care

Exercise capacity in ATTR is limited by cardiac and neurological involvement. But appropriate exercise remains important for:

• Maintaining muscle mass (sarcopenia accelerates with inactivity)
• Improving insulin sensitivity
• Supporting cardiac function within safe limits
• Reducing depression and improving quality of life

Essential: Cardiac assessment before exercising. ATTR cardiomyopathy is different from typical hypertrophic cardiomyopathy — it causes a restrictive filling pattern, and the heart cannot increase stroke volume during exercise the way a normal heart can. Exercise tolerance is therefore genuinely limited and must be respected.

What Is Generally Safe

• Walking: The gold standard. Flat surfaces at a comfortable pace. Use a pulse oximeter to monitor heart rate — keep it within limits set by your cardiologist. Even 15–20 minutes daily has meaningful benefit.
• Seated or recumbent cycling: Reduces orthostatic stress compared to upright exercise. Ideal for those with postural hypotension from autonomic neuropathy.
• Light resistance exercise: Resistance bands or light dumbbells — seated where possible. Avoid the Valsalva manoeuvre. Focus on maintaining functional muscle, not building bulk.
• Yoga / tai chi: Balance improvement is important because peripheral neuropathy increases fall risk. Tai chi has evidence for balance in neuropathy populations.
• Hydrotherapy: Warm water reduces orthostatic hypotension effects and supports weak limbs. Always with supervision.

What to Avoid

• High-intensity exercise: The amyloid-infiltrated heart cannot increase cardiac output adequately under strenuous demand — this is dangerous
• Exercise in heat: Autonomic neuropathy impairs thermoregulation and sweating — avoid hot outdoor exercise; use air-conditioned environments
• Activities with fall risk: Peripheral neuropathy causes poor proprioception — avoid uneven surfaces, running, and sports with quick directional changes
• Prolonged standing: Orthostatic hypotension makes prolonged upright postures risky — rest regularly, rise slowly from seated/lying positions

Diet for ATTR Amyloidosis

For Those Who Are Overweight: Gradual, Gentle Deficit

If your cardiologist and dietitian agree that moderate weight loss is appropriate:

• Aim for 0.25–0.5 kg per week maximum — faster loss in cardiac disease causes muscle wasting and electrolyte shifts
• Never fast or skip meals — hypotension risk from autonomic neuropathy worsens with prolonged fasting
• Use a mild calorie deficit: reduce by 250–300 kcal/day through portion control, not food elimination

Cardiac-Protective Eating

• Low sodium: Most important dietary intervention for cardiac amyloidosis. Target under 1 500–2 000 mg/day. Fluid retention from heart failure worsens with high sodium intake. Avoid processed meats, canned soups, salty snacks, biltong (unfortunately — or have a small amount), takeaways, and fast food.
• Fluid management: Your cardiologist may specify a daily fluid limit (often 1.5–2 L/day) to prevent fluid overload. Track intake.
• Mediterranean pattern: Olive oil, fish, vegetables, legumes, wholegrains. Anti-inflammatory and cardioprotective. Snoek, pilchards, and salmon are excellent and affordable in SA.
• Limit alcohol entirely: Alcohol is directly cardiotoxic and worsens amyloid cardiomyopathy. Even moderate drinking should be discussed with your cardiologist — many experts recommend complete abstinence in ATTR.

For Those with GI Involvement: Nutrition First

If GI amyloid is causing malabsorption, diarrhoea, or weight loss:

• Small, frequent meals: 5–6 small meals rather than 3 large ones — reduces early satiety and nausea
• Calorie-dense foods: Avocado, nut butters, full-cream dairy, olive oil — add calories without large volumes
• Oral nutritional supplements: Ensure, Fresubin, or Fortisip — available at Dis-Chem and Clicks — provide concentrated nutrition in small volumes
• High protein: Aim for 1.5–2 g/kg bodyweight to counter catabolism and muscle wasting. Eggs, soft fish, amasi, protein powder in smoothies.
• Low-fat diet if diarrhoea is prominent: Fat malabsorption may contribute to steatorrhoea — discuss with your gastroenterologist and dietitian
• Probiotic foods: Amasi, kefir, and plain yoghurt may help manage GI dysmotility symptoms

Autonomic Neuropathy and Eating

• Postprandial hypotension (blood pressure drop after eating) is common with autonomic neuropathy. To reduce it: eat smaller meals, reduce refined carbohydrates, remain seated for 30–60 minutes after eating, avoid alcohol at meals.
• Compression stockings during meals can help maintain blood pressure if postprandial hypotension is problematic.

Disease-Modifying Treatments in South Africa

This is where ATTR differs dramatically from older descriptions of the disease — effective treatments now exist:

• Tafamidis (Vyndaqel/Vyndamax): A TTR stabiliser that has been shown to reduce cardiovascular mortality and hospitalisations in ATTR cardiomyopathy. Currently available in SA through specialist (private) cardiologists — very expensive, not on formulary. Medical aid motivation required.
• Patisiran (Onpattro): RNA interference therapy — reduces TTR production by the liver. Approved for ATTRv polyneuropathy. Not routinely available in SA yet.
• Inotersen (Tegsedi): Antisense oligonucleotide — reduces TTR production. Same status as patisiran in SA.
• Vutrisiran (Amvuttra): Newer siRNA with less frequent dosing — available internationally, not yet in SA.

Tafamidis is the most likely option available to South African patients currently. If you have a confirmed ATTR diagnosis, ask your cardiologist about tafamidis and explore medical aid coverage. The sooner treatment starts, the more cardiac function can be preserved.

The Val122Ile Variant: A South African Priority

The TTR Val122Ile variant (carried by approximately 3–4% of people of West African descent) causes cardiac-predominant ATTR amyloidosis, typically presenting in the sixth or seventh decade with heart failure, arrhythmias, and carpal tunnel syndrome. It is estimated that this variant affects millions of people of African ancestry worldwide, but is dramatically underdiagnosed.

If you are Black African and have:

• Heart failure with preserved ejection fraction (HFpEF)
• Unexplained left ventricular hypertrophy on echo
• History of carpal tunnel syndrome (especially bilateral)
• Family history of heart failure in older relatives

...then TTR gene sequencing and cardiac amyloid investigation should be requested. Ask your cardiologist or internist specifically about the Val122Ile variant. NHLS can perform TTR gene sequencing.

Finding Help in South Africa

• Cardiologist/Heart failure specialist: For ATTR cardiomyopathy management, echo, DPD scan referral, and tafamidis initiation
• Neurologist: For peripheral and autonomic neuropathy management in ATTRv
• Gastroenterologist: For GI amyloid manifestations and nutrition support
• NHLS molecular genetics: For TTR gene sequencing — request from your specialist
• Registered Dietitian: Critical for managing both cardiac dietary restrictions and nutritional support if GI involvement is present — adsa.org.za
• Nuclear medicine: For DPD scintigraphy (diagnostic scan) — Groote Schuur, Charlotte Maxeke, Steve Biko, IALCH Durban
• Amyloidosis support: Amyloidosis Research Consortium (amyloidosis.org) and Amyloidosis Foundation (amyloidosis.com) — international resources with patient guides

Key Takeaways

• ATTR amyloidosis is underdiagnosed in South Africa — the Val122Ile variant disproportionately affects people of Black African ancestry
• The primary weight concern is often preventing unintentional weight loss from GI amyloid and cardiac cachexia — report any unexplained weight loss to your doctor immediately
• If overweight, a gentle deficit (0.25–0.5 kg/week max) is safe; never crash diet with cardiac amyloidosis
• Low sodium diet is the most important dietary intervention for cardiac protection
• Avoid alcohol entirely — it is cardiotoxic in ATTR
• Walking and seated cycling are the safest exercise options — avoid high intensity and fall-risk activities
• Ask your cardiologist about tafamidis — early treatment preserves heart function
• Small, frequent calorie-dense meals help those with GI involvement maintain nutrition