Iodine Deficiency Is Higher in Morbid Obesity in Comparison with Late After Bariatric Surgery and Non-obese Women

Iodine deficiency and obesity are worldwide-occurring health problems. Our purpose was to investigate the relationship between morbid obesity and iodine status, including subjects who lost weight after bariatric surgery.

Ninety morbidly obese women, 90 women with at least 18 months follow-up after bariatric surgery, and 45 healthy non-obese women were recruited. Urinary iodine concentration (UIC) was measured in a spot urinary sample and expressed as the iodine-to-creatinine ratio.

Obese women showed a significantly lower UIC in comparison with non-obese women (96.6 (25.8–267.3) vs. 173.3 (47.0–493.6) μg/g; p < 0.001), with a lesser proportion of subjects with adequate iodine status (46.6 vs. 83.3 %, p < 0.001). The mean UIC significantly increased among women who underwent bariatric surgery before the collection of the urinary sample (96.6 (25.8–267.3) vs. 131.9 (62.9–496.4) μg/g; p < 0.001). No difference in UIC was detected between laparoscopic Roux-en-Y gastric bypass and laparoscopic sleeve gastrectomy. Univariate analysis showed that UIC negatively correlated with body mass index (BMI) (r = −0.278, p < 0.001) and positively with age (r = 0.206, p = 0.002). Finally, multiple linear regression analyses showed that BMI was independently associated with UIC (beta = −0.312, p < 0.001; R ² = 0.166).

Obesity is an independent risk factor to iodine deficiency, almost in women. Whether more obese population needs to be considered as a vulnerable group and whether bariatric surgery can reverse iodine deficiency still remain to be elucidated.