Prevalence of nutritional deficiencies in bariatric surgery candidates and its effect on metabolic status

Nutritional deficiencies are common among obese individuals and constitute one of the main concerns in the bariatric field. The aim of this study was to investigate nutritional status in bariatric surgery candidates, comparing individuals with and without metabolic syndrome (MetS) and to explore possible associations between nutritional and metabolic status.

Patients accepted for gastric sleeve surgery between 2010 and 2015 were included and anthropometric and metabolic parameters were recorded before surgery. Univariate and multivariate analyses were applied in order to find possible associations between MetS, nutritional, anthropometric, and metabolic parameters.

A total of 330 patients were evaluated (285 females, mean age of 41.88 ± 10.4 years old, mean body mass index 43.91 ± 6.2 kg/m²) and MetS was present in 47% of them. Patients without MetS presented a higher prevalence of folate deficiency (12 vs. 2%, p < 0.001). Male gender, older age, lower magnesium levels, and higher BMI and calcium levels were predictors of a greater number of MetS components. Male gender, a greater number of MetS components, and lower magnesium were predictors of higher homeostatic model assessment for insulin resistance (HOMA-IR).

The rising prevalence of obesity is causing a parallel increase in the use of bariatric surgery. The high occurrence of preoperative nutritional deficiencies can impair metabolic status and contribute to a worse outcome after surgery. Nutritional assessment and improvement before surgery may be crucial to optimize patient status, and future studies should explore the effect of the correction of these deficiencies in the metabolic status of these patients.