Progress in treatment of type 2 diabetes by bariatric surgery

Table 1 Randomized controlled trials of bariatric surgery vs medical treatment for type 2 diabetes

Ref.	Intervention	Control	Follow-up in mo	Diabetes remission, surgery vs control (%)
Parikh et al[30], 2014	VSG	Medication	6	65 vs 0
Simonson et al[25], 2019	AGB	Medication	12	33 vs 23
Cummings et al[28], 2016	RYGB	Medication	12	60 vs 6
Mingrone et al[29], 2015	BPD; RYGB	Medication	24	95 vs 0; 75 vs 0

AGB: Adjustable gastric banding; BPD: Biliopancreatic diversion; RYGB: Roux-en-Y gastric bypass; VSG: Vertical sleeve gastrectomy.

Table 2 Several factors contributing to improved type 2 diabetes after bariatric surgery

Target	Major site of secretion (anatomical location)	VSG	RYGB
Ghrelin	X/A-like cells (stomach)	Decrease	Decrease or no change
GLP1	L cells (distal gut)	Increase	Increase
PYY	L cells (distal gut)	Increase	Increase
Bile acids	Hepatocytes	Increase	Increase
FGF-15/19	Ileum	Increase	Increase
Microbiota	Gut	Change	Change
Enteroplasticity	Gut	Change	Change

Multiple factors appear to drive the remission of type 2 diabetes after bariatric surgery, including decreased ghrelin, increased glucagon-like peptide, increased peptide-YY, increased bile acids, increased fibroblast growth factor-15/19, and alteration of microbiota and enteroplasticity. Data are derived from both human and animal studies. GLP1: Glucagon-like peptide 1; FGF: Fibroblast growth factor; PYY: Peptide-YY; RYGB: Roux-en-Y gastric bypass; VSG: Vertical sleeve gastrectomy.