Semaglutide cut heart attack risk by 20% — but weight loss explains less than half of it

Key Findings

GLP-1 drugs linked to sharply lower tuberculosis risk 🦠

• A multicenter cohort study across 143 healthcare organizations found that people with type 2 diabetes on GLP-1 drugs had tuberculosis incidence rates roughly half those of patients on sulfonylureas or DPP-4 inhibitors over up to 5 years.
• The association held across multiple comparators including metformin and SGLT-2 inhibitors, though the gap was smaller with the latter.

Tirzepatide: 21% weight loss, but stopping means gaining it back

• A systematic review of 26 publications across 11 studies found tirzepatide produced mean weight loss approaching 21% after 72 weeks, with benefits extending to cardiometabolic risk factors, body composition, and quality of life.
• The pattern was consistent across randomized trials and real-world cohorts — but treatment discontinuation led to progressive weight regain in every study that tracked it.

A new RNA therapy preserved lean mass while GLP-1 drugs cut fat (in mice)

• Researchers used antisense oligonucleotides targeting a gene called ZFP423 — a repressor of fat-burning in adipose tissue — to activate thermogenesis in obese mice.
• When combined with semaglutide, the combination produced greater fat loss than either treatment alone while preserving lean mass, a persistent weakness of GLP-1 monotherapy. This is animal data; human translation is unproven.

Patients with the most to gain from GLP-1 drugs are often last in line

• An editorial in Cureus argues that patients with type 2 diabetes and chronic kidney disease — a group with strong clinical trial evidence for benefit — are routinely outcompeted for GLP-1 drug access by a consumer market organized around elective weight loss.
• At list price, cost-effectiveness analyses place these drugs above accepted value thresholds, meaning kidney risk rarely determines who gets a prescription.

GLP-1 drugs may slow dementia progression in people who already have memory problems

• A target-trial emulation study found that GLP-1 drug therapy was associated with reduced progression to dementia in people with both type 2 diabetes and mild cognitive impairment — a different population than the EVOKE trials, which tested oral semaglutide in early Alzheimer's patients mostly without diabetes and found no benefit.
• The divergence suggests the cognitive signal may be specific to diabetes-related pathways rather than Alzheimer's biology broadly.

Hair loss on GLP-1 drugs: real, but manageable and less common than after surgery

• About 3–5% of patients in pivotal trials experienced hair loss on GLP-1 drugs, with a pooled risk roughly 3.3 times higher than placebo. The main driver appears to be rapid caloric restriction triggering a temporary shedding phase, not a direct drug effect on hair follicles.
• For comparison, pooled hair loss rates after bariatric surgery run 47–57%. Protein intake targets of 1.2–2.0 g/kg/day and low-dose oral minoxidil are flagged as management options.