Levothyroxine therapy and impaired clearance are the strongest contributors to small intestinal bacterial overgrowth: Results of a retrospective cohort study

Table 5 Miscellaneous variables

	SIBO		Non-SIBO		χ2 test	OR	RR
	n = 175	%	n = 1634	%	P value
Thyroid gland surgery	7	4.0	33	2.0	0.0852	2.021	0.505
Hypothyroidism	17	9.7	66	4.0	0.0021	2.556	0.416
Hyperthyroidism	1	0.6	24	1.5	0.287	-	-
Levothyroxine use	30	17.1	106	6.5	< 0.0011	2.982	0.378
Adipositas	31	17.7	307	18.8	0.410	-	-
Diabetes mellitus	25	14.3	132	8.1	0.0061	1.896	0.565
Steatosis hepatis	22	12.6	158	9.7	0.139	-	-
Hepatitis	7	4.0	61	3.7	0.492	-	-
Liver cirrhosis	2	1.1	35	2.1	0.289	-	-
Renal insufficiency	2	1.1	16	1.0	0.532	-	-
Colonic diverticulosis	6	3.4	37	2.3	0.229	-	-
Sigmoid diverticulosis	8	4.6	151	9.2	0.0201	0.470	2.021
Crohn’s disease	19	10.9	134	8.2	0.146	1.363	0.755
Ulcerative colitis	2	1.1	52	3.2	0.0922	0.352	2.785
Alcoholism	3	1.7	36	2.2	0.468	-	-
Smokers	10	5.7	52	3.2	0.0702	1.844	0.557
NSAID use	29	16.6	284	17.4	0.442	-	-
Laxative use	3	1.7	58	3.5	0.142	-	-
Antidiarrhoics use	9	5.1	118	7.2	0.195	-	-
Spasmolytics use	9	5.1	257	15.7	< 0.0011	0.290	3.058
Antiemetics use	22	12.6	144	8.8	0.0712	1.488	0.701
Irritable bowel syndrome	8	4.6	322	19.7	< 0.0011	0.195	4.311

¹Statistical significant with P-value P < 0.05;

²Statistical tendency with P-value 0.05 < P < 0.1 χ² test each. Patients with hypothyroidism and substitution of levothyroxine show a higher risk of SIBO. In the case of thyroidectomy, statistical significance was not achieved. The presence of diverticulosis of the sigmoid, but not of the entire colon was associated with a decreased risk of SIBO. Patients with Crohn’s disease did not exhibit a higher prevalence of SIBO, and ulcerative colitis tended to be protective, but did not reach statistical significance. Patents without SIBO were more likely to use spasmolytics and to suffer from irritable bowel syndrome. SIBO: Small intestinal bacterial overgrowth; NSAID: Non-steroidal anti-inflammatory drugs.