The effects of laparoscopic Roux-en-Y gastric bypass and one-anastomosis gastric bypass on glycemic control and remission of type 2 diabetes mellitus: study protocol for a multi-center randomized controlled trial (the DIABAR-trial)

Table 1 Study procedures in the Spaarne Gasthuis and the Franciscus Gasthuis

		Enrolment allocation	Post-allocation
Timepoint		t=-2	t = -1	t = 0	t = 1	t = 2	t = 3	t = 4	t = 5	t=6-9	t=10
	Medical center	Screening	< 42 days of surgery	Day of surgery	14 D	42 D	6 M	1 Y	2 Y	3,4,5,10 Y	Re-operation^a/endoscopy
Enrolment/allocation
Eligibility screen	SG/FG	x
Informed consent and allocation	SG/FG	x
Demographics
Medical history	SG/FG	Reg	x				x	x	x	x
Medication check	SG/FG	Reg	x	x	x	x	x	x	x	x	x
Biometrics
Physical examination	SG/FG	x	x	x		x	x	x	x	x
CO/SVR/BS	SG		x					x	x
Blood
Laboratory work	SG/FG	Reg		Reg			Reg	Reg	Reg	Reg	Reg
MMT	SG		x					x	x
Extra blood samples	SG		x	x				x	x	x	x
Questionnaires
Psychological questionnaires	SG/FG		x				x	x	x	x
GIQLI	SG/FG		x					x	x	x
Dietary and satiety list	SG		x					x	x
Oral, fecal, and urine samples
Urine sample	SG				x	x	x			x
Feces sample	SG				x	x	x			x
24-h feces and urine	SG			x				x	x
Oral microbiome	SG		x					x	x	x
Surgery and tissue samples
RYGB or OAGB	SG/FG			x
Small intestine tissue sample	SG			x							x^a
Subcutaneous adipose tissue	SG			x				x	x		x
Visceral adipose tissue	SG			x							x
Omental tissue	SG			x							x
Liver biopsy	SG			x						x	x
Portal blood sample	SG			x^a							x^a
Bile acids and bile salts	SG			x^a							x^a
Surgical endpoints	SG/FG				x	x	x	x	x	x
Other
Ultrasound gallbladder	SG		x^a					x^a	x^a

BS baroreflex sensitivity, MMT mixed meal test, D days, CO cardiac output, GIQLI gastro-intestinal quality of life, FG Franciscus Gasthuis, FU follow-up, M months, OAGB one-anastomosis gastric bypass, SG Spaarne Gasthuis, SVR systemic vascular resistance, RYGB Roux-en-Y gastric bypass, Reg regular, t time, Y year
^aIf applicable

ISSN: 1745-6215