The influences of bariatric surgery on hemoglobin A1c in a sample of obese patients in Saudi Arabia

Figures & data

Table 1 Patient characteristics (N=318)

Characteristics	Levels	n	%
Sex	Female	215	67.6
	Male	103	32.4
Bariatric procedure	RYGB	37	11.6
	LSG	281	88.4
Diabetes	No	258	81.6
	Yes	58	18.4
Asthma	No	272	86.1
	Yes	44	13.9
Obstructive sleep apnea	No	291	92.1
	Yes	25	7.9
BMI reduction, kg/m^2	0–9	113	43.0
	10–14	68	25.9
	>14	82	31.1
		Mean	±SD
Age (13–64), years		34.7	11.7
Baseline BMI (32.7–83.1), kg/m^2		46.8	7.7
Baseline HbA1c (2.5–14), %		6.7	2.1

Abbreviations: BMI, body mass index. LSG, laparoscopic sleeve gastrectomy; HbA1c, hemoglobin A1c; RYGB, Roux-en-Y gastric bypass.

Figure 1 Changes in HbA1c by visit, diabetes status, body mass index (kg/m²) reduction, and procedure type after bariatric surgery.

Notes: (A) We observed significantly greater reduction in HbA1c in patients with diabetes than those without diabetes. (B) Diabetic patients had significantly higher HbA1c than non-diabetic patients at the baseline, whereas diabetic patients had insignificantly higher HbA1c than non-diabetic patients following the surgical procedure. (C) In those who had greater reduction in BMI (10–14 and >14 kg/m²), we observed insignificant differences in HbA1c levels between diabetic patients and non-diabetic patients. (D) There was a significant difference in HbA1c within the LSG and RYGB groups between baseline and following the surgical procedure, while there was insignificant difference between the LSG and RYGB groups in the HbA1c preoperatively and postoperatively.
Abbreviations: BMI, body mass index; HbA1c, hemoglobin A1c; LS-means, least squares-means.

Table 2 Factors associated with the change in HbA1c using mixed-effects model

	B	SE	t-value	P-value
Intercept	6.343	0.651	9.740	0.001
Main effects
Age	0.013	0.010	1.300	0.206
Female	–0.194	0.240	–0.810	0.426
LSG	–1.181	0.486	–2.430	0.022*
Diabetes	3.628	0.406	8.940	0.001*
Asthma	–0.390	0.305	–1.280	0.212
Obstructive sleep apnea	0.697	0.410	1.700	0.100
Postoperative visit	–1.717	0.598	–2.870	0.008*
BMI reduction 10–14 kg/m^2	0.210	0.329	0.640	0.528
BMI reduction >14 kg/m^2	0.349	0.333	1.050	0.304
Interaction effects
Diabetes × postoperative visit	–1.911	0.393	–4.860	0.001*
Diabetes×BMI reduction 10–14 kg/m^2	–1.560	0.580	–2.690	0.012*
Diabetes×BMI reduction >14 kg/m^2	–1.717	0.528	–3.250	0.003*
LSG × postoperative visit	1.497	0.596	2.510	0.018*

Note:

* Significant at α=0.05.

Abbreviations: BMI, body mass index; HbA1c, hemoglobin A1c; LSG, laparoscopic sleeve gastrectomy; SE, standard error.