LACTATE CAN BE A MARKER OF METABOLIC SYNDROME IN SEVERE OBESITY?

BACKGROUND: In the last decades, numerous studies have confirmed the importance of lactate - by-product to the nutrient signal of the intracellular redox state - to regulatory functions in energy metabolism. AIM: To evaluate changes in blood lactate in patients with severe obesity and its correlation with body composition and metabolic profile. METHODS: Twenty-four people with severe obesity (BMI=40 kg/m2) were evaluated in a prospective case-control study before and six months after Roux-in-Y gastric bypass. The blood lactate, total cholesterol, and fractions, C-reactive protein and HOMA-IR were analyzed after 12 h fasting. Body mass composition was evaluated by bioelectrical impedance and respiratory quotient was measured by indirect calorimetry. RESULTS: The initial lactate level was 2.5±1.1 mmol/l and returned to normal level (1.9±3.6 mmol/l, p=0.0018) after surgery. This reduction was positively correlated with a decrease in BMI (p=0.0001), % free fat mass (p=0,001), % fat mass (p=0.001) and HOMA-IR (p=0.01). There was normalization of lactatemia in 70% of patients. There was no correlation between lactatemia and C-reactive protein. CONCLUSIONS: There was a significant improvement of metabolic parameters, normalization of blood lactate, fat mass loss, although these individuals remained with a high BMI.

Lactate can be a marker of metabolic syndrome in severe obesity? / Lactato pode ser marcador da síndrome metabólica na obesidade grave?

ABSTRACT Background: In the last decades, numerous studies have confirmed the importance of lactate - by-product to the nutrient signal of the intracellular redox state - to regulatory functions in energy metabolism. Aim: To evaluate changes in blood lactate in patients with severe obesity and its correlation with body composition and metabolic profile. Methods: Twenty-four people with severe obesity (BMI=40 kg/m2) were evaluated in a prospective case-control study before and six months after Roux-in-Y gastric bypass. The blood lactate, total cholesterol, and fractions, C-reactive protein and HOMA-IR were analyzed after 12 h fasting. Body mass composition was evaluated by bioelectrical impedance and respiratory quotient was measured by indirect calorimetry. Results: The initial lactate level was 2.5±1.1 mmol/l and returned to normal level (1.9±3.6 mmol/l, p=0.0018) after surgery. This reduction was positively correlated with a decrease in BMI (p=0.0001), % free fat mass (p=0,001), % fat mass (p=0.001) and HOMA-IR (p=0.01). There was normalization of lactatemia in 70% of patients. There was no correlation between lactatemia and C-reactive protein. Conclusions: There was a significant improvement of metabolic parameters, normalization of blood lactate, fat mass loss, although these individuals remained with a high BMI.

RESUMO Racional: Nas últimas décadas, inúmeros estudos confirmam a importância do lactato - subproduto ao sinal de nutrientes do estado redox intracelular - às funções reguladoras do metabolismo energético. Objetivo: Avaliar alterações no lactato sanguíneo em pacientes com obesidade grave e sua correlação com a composição corporal e o perfil metabólico. Métodos: Vinte e quatro pacientes com obesidade grave (IMC=40 kg/m2) foram avaliadas em um estudo prospectivo antes e após seis meses do bypass gástrico em Y-de-Roux. O lactato sanguíneo, colesterol total e frações, proteína C-reativa e HOMA-IR foram analisados após 12h de jejum. A composição corporal foi avaliada por bioimpedância elétrica e o quociente respiratório por calorimetria indireta. Resultados: O nível inicial de lactato foi de 2,5±1,1 mmol/l e retornou ao nível normal após a operação (1,9±3,6 mmol/l, p=0,0018). Essa redução foi correlacionada positivamente com a diminuição do IMC (p=0,0001), % de massa livre de gordura (p=0,001) e % de massa de gordura (p=0,001) e HOMA-IR (p=0,01). Houve normalização da lactatemia em 70% dos pacientes. Não houve correlação entre lactatemia e proteína C-reativa. Conclusões: Houve melhora significativa dos parâmetros metabólicos e normalização da lactatemia, perda de massa gorda, embora esses indivíduos permanecessem com IMC elevado.