Estado nutricional de vitaminas lipossolúveis e cobalamina na Síndrome da Quilomicronemia Familiar (SQF): um estudo caso controle

Abstract

Familial Chylomicronemia Syndrome (FCS) is a rare autosomal recessive genetic disorder primarily caused by mutations in the lipoprotein lipase (LPL) gene or genes related to its function, resulting in severe hypertriglyceridemia. FCS management requires rigorous nutritional therapy with severe lipid restriction (less than 20 g per day) that can directly impact the intake and absorption of fat-soluble vitamins and cobalamin. This study aimed to evaluate the nutritional status of fat-soluble vitamins and cobalamin in individuals with FCS compared to healthy individuals. A case-control study matched by sex, age, and BMI category (1:1) was conducted, including 11 FCS patients matched with their respective controls (n=11), with participants recruited from Onofre Lopes University Hospital (HUOL) and the Federal University of Rio Grande do Norte (UFRN). Individuals with FCS were grouped according to genotypic alteration, being classified as heterozygotes or homozygotes. Data on lifestyle, health, physical examination, gastrointestinal symptoms, anthropometric assessment, and dietary intake were collected. Blood samples were obtained for biochemical analysis of the following vitamins: serum retinol, serum phylloquinone, serum alpha-tocopherol, 25-hydroxyvitamin D, and serum cobalamin. Data were analyzed using SPSS Statistics v.26.0 software, adopting a 95% significance level (p < 0.05). Effect size was calculated using Cohen's d, Cliff's Delta, Eta squared, and Epsilon squared. A large effect size was observed for retinol, with the heterozygote group showing higher levels compared to the homozygote and control groups. There was also a large effect size for alpha-tocopherol, where heterozygote and homozygote groups presented higher levels than the control group, the latter showing possible insufficiency of this vitamin according to the adopted cutoff points. Additionally, an inversely proportional correlation was identified between vitamin D and triglyceride, total cholesterol, and VLDL levels, as well as a directly proportional correlation between cobalamin and serum retinol. Regarding food consumption, it was verified that individuals with FCS had lipid intake above the recommended nutritional guidance of 20g/day. Thus, individuals with FCS presented significantly elevated concentrations of alpha-tocopherol and serum retinol compared to controls, with heterozygotes showing even higher retinol levels. Dietary lipid consumption exceeded nutritional recommendations by more than twice, suggesting an inadequate dietary pattern that may contribute to the syndrome's metabolic alterations.