Role of childhood growth on the risk of metabolic syndrome in obese men and women

Abstract

Aim

Although obesity is the key characteristic of the metabolic syndrome, not all obese individuals develop the syndrome. Our aim was to identify characteristics of early growth that protect these individuals from the metabolic syndrome.

Methods

We examined 2003 subjects born in Helsinki, Finland, between 1934 and 1944. We focused on the 499 who were obese (BMI ≥ 30 kg/m²), 400 of whom had the metabolic syndrome according to IDF 2005 criteria. The subjects had a median of seven measurements of height and weight from birth to two years of age, and eight measurements from two to 11 years of age.

Results

Among obese individuals, those with the metabolic syndrome had a higher mean body mass index (BMI) and larger waist circumference than those who did not. The two groups were similar in body size at birth but, by two years of age, those who later developed the metabolic syndrome were lighter and thinner, and remained so up to age 11 years. The period when BMI changes were predictive of the syndrome was from birth to seven years. OR was 0.72 (95% CI: 0.57–0.92) per 1 S.D. increase in BMI from birth to two years and 0.63 (95% CI: 0.49–0.81) per 1 S.D. increase in BMI from two to seven years.

Conclusion

Among obese individuals, those who develop the metabolic syndrome were lighter and thinner from the age of two to 11 years compared with those who did not. These findings support the importance of early childhood growth in determining the metabolic consequences of obesity.

Résumé

Objectif

Bien que l’obésité constitue une caractéristique essentielle du syndrome métabolique, ce syndrome n’est pas observé chez tous les individus obèses. Notre objectif était d’identifier les caractéristiques des premières années de croissance qui protègent les individus obèses du syndrome métabolique.

Méthodes

Nous avons examiné 2003 sujets nés à Helsinki en Finlande entre 1934 et 1944. Nous nous sommes penchés plus particulièrement sur les 499 sujets obèses (IMC > 30 kg/m²) ; 400 d’entre eux étaient atteints du syndrome métabolique selon la définition de l’IDF (2005). La taille et le poids de chaque sujet ont été mesurés sept fois (médiane) de zéro à deux ans et huit fois de deux à 11 ans.

Résultats

L’IMC moyen ainsi que le tour de taille étaient plus élevés chez les sujets obèses atteints du syndrome métabolique. Les deux groupes avaient des tailles comparables à la naissance, mais à l’âge de deux ans, les sujets plus tard atteints du syndrome métabolique avaient un poids inférieur et étaient plus minces. Cette différence a été observée jusqu’à l’âge de 11 ans. La modification de l’IMC qui annonce le syndrome métabolique s’opérait entre zéro et sept ans. Le rapport de cotes (RC) était de 0,72, (IC à 95 % 0,57–0,92) selon l’augmentation de l’écart type de l’IMC de zéro à deux ans ; le RC était de 0,63 (IC à 95 % 0,49–0,81) selon l’augmentation de l’IMC de deux à sept ans.

Conclusion

Parmi les sujets obèses, ceux qui ont été atteints du syndrome métabolique étaient plus légers et plus minces de deux à 11 ans. Ces résultats confirment l’importance des premières années de croissance dans la compréhension des conséquences métaboliques de l’obésité.

Introduction

Obesity is reaching epidemic proportions worldwide and, as a consequence, there is expected to be a rapid increase in type 2 diabetes and cardiovascular disease [1]. This is mainly due to the fact that obesity is associated with the metabolic syndrome. It is, however, apparent that not all overweight and obese individuals develop either the metabolic syndrome or type 2 diabetes [2], [3], [4], [5]. Depending on the definitions applied and the study population assessed, approximately 10–40% of overweight individuals have been described as metabolically normal [5], [6], [7], [8]. The concept of metabolically normal yet overweight/obese (MNO) individuals refers to a subgroup of obese people with relatively high degrees of insulin sensitivity and a favourable metabolic profile [8], [9]. The recognition of this MNO phenotype could help to identify factors that protect against the metabolic syndrome. However, the origin of the phenotype is still unknown. The developmental origins of health and disease (DOHaD) hypothesis proposes that adverse health outcomes in adult life are partly programmed during fetal life and infancy [10], [11]. To our knowledge, only one previous study has focused on the question from a DOHaD perspective. In that study, Hayes and co-workers could find no evidence of the role of early life experience in explaining the MNO phenotype. However, they had only limited data on early growth [12]. The aim of the present study was to identify the early life characteristics that protect individuals who become obese against the metabolic syndrome.