Lifestyle Determinants of Serum Insulin-Like growth-factor-I (IGF-I), C-peptide and Hormone Binding Protein Levels in British Women

Cancer Causes Control. 2003 Feb;14(1):65-74. doi: 10.1023/a:1022518321634.

Abstract

Objective: This study aims to identify the lifestyle determinants of insulin-like growth factor-I (IGF-I) and its main binding proteins (IGFBPs), C-peptide, and sex hormone-binding globulin (SHBG) to help elucidate the mechanism through which lifestyle factors may affect cancer risk.

Methods: This study is based on a sample of 292 British women, aged 20-70 years, whose lifestyle characteristics were assessed using a self-administered questionnaire and whose serum hormone concentrations were measured using immunoassays.

Results: Age was a strong determinant of both IGF-I and IGFBP levels; women aged 65-70 years had significantly lower IGF-I and IGFBP-3 concentrations and significantly higher IGFBP-1 and IGFBP-2 concentrations than women aged 20-24 years. Body mass index (BMI) was not strongly associated with IGF-I, although women with a BMI of 26-27.9 kg/m2 had a higher IGF-I concentration compared with both lean (BMI <20 kg/m2) and obese (BMI 30+ kg/m2) women. However, obese women had a significantly higher C-peptide and IGFBP-3 concentration and a significantly lower IGFBP-1, IGFBP-2, and SHBG concentration compared with lean women. Increasing vigorous exercise was associated with a significantly lower C-peptide concentration and increasing leisure-time activity was associated with a significantly higher IGFBP-1 concentration. Other lifestyle factors such as job activity, smoking, and reproductive factors were not associated with any hormone.

Conclusions: Our data show that age is a major determinant of both IGF-I and its main binding proteins in women. BMI has strong effects on IGFBPs, C-peptide, and SHBG, but its effects on IGF-I remain unclear. The possible effect of physical activity on IGFBP-1 requires further investigation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Age Factors
  • Body Mass Index
  • C-Peptide / blood
  • C-Peptide / metabolism*
  • Female
  • Humans
  • Insulin-Like Growth Factor Binding Protein 1 / blood
  • Insulin-Like Growth Factor Binding Protein 1 / metabolism*
  • Insulin-Like Growth Factor I / analysis
  • Insulin-Like Growth Factor I / physiology*
  • Life Style*
  • Middle Aged
  • Motor Activity
  • Neoplasms / epidemiology*
  • Neoplasms / metabolism*
  • Risk
  • Sex Hormone-Binding Globulin / analysis
  • Sex Hormone-Binding Globulin / metabolism*
  • United Kingdom / epidemiology

Substances

  • C-Peptide
  • Insulin-Like Growth Factor Binding Protein 1
  • Sex Hormone-Binding Globulin
  • Insulin-Like Growth Factor I