Prevalence, Metabolic Features, and Prognosis of Metabolically Healthy Obese Italian Individuals
The Cremona Study
- Giliola Calori, MD1,
- Guido Lattuada, PHD1,2,
- Lorenzo Piemonti, MD3,
- Maria Paola Garancini, MD4,
- Francesca Ragogna, PHD1,
- Marco Villa, MD5,
- Salvatore Mannino, MD5,
- Paolo Crosignani, MD6,
- Emanuele Bosi, MD1,
- Livio Luzi, MD1,2,
- Giacomo Ruotolo, MD1,7 and
- Gianluca Perseghin, MD1,2
- 1Division of Metabolic and Cardiovascular Sciences, Istituto Scientifico H San Raffaele, Milan, Italy;
- 2Department of Sport Sciences, Nutrition, and Health, Università degli Studi di Milano, Milan, Italy;
- 3Diabetes Research Institute, Istituto Scientifico H San Raffaele, Milan, Italy;
- 4Medical Direction, Istituto Scientifico H San Raffaele, Milan, Italy;
- 5Servizio Epidemiologia ASL della Provincia di Cremona, Istituto Einaudi, Cremona, Italy;
- 6Istituto Nazionale dei Tumori, Milan, Italy;
- 7Department of Research and Development, AstraZeneca, Molndal, Sweden.
- Corresponding author: Gianluca Perseghin, .
OBJECTIVE Some obese individuals have normal insulin sensitivity. It is controversial whether this phenotype is associated with increased all-cause mortality risk.
RESEARCH DESIGN AND METHODS Fifteen-year all-cause mortality data were obtained through the Regional Health Registry for 2,011 of 2,074 Caucasian middle-aged individuals of the Cremona Study, a population study on the prevalence of diabetes in Italy. Individuals were divided in four categories according to BMI (nonobese: <30 kg/m2; obese: ≥30 kg/m2) and estimated insulin resistance (insulin sensitive: homeostasis model assessment of insulin resistance <2.5; insulin resistant ≥2.5).
RESULTS Obese insulin-sensitive subjects represented 11% (95% CI 8.1–14.5) of the obese population. This phenotype had similar BMI but lower waist circumference, blood pressure, fasting glucose, triglycerides, and fibrinogen and higher HDL cholesterol than obese insulin-resistant subjects. In the 15-year follow-up, 495 deaths (cardiovascular disease [CVD]: n = 221; cancer: n = 180) occurred. All-cause mortality adjusted for age and sex was higher in the obese insulin-resistant subjects (hazard ratio 1.40 [95% CI 1.08–1.81], P = 0.01) but not in the obese insulin-sensitive subjects (0.99 [0.46–2.11], P = 0.97) when compared with nonobese insulin-sensitive subjects. Also, mortality for CVD and cancer was higher in the obese insulin-resistant subjects but not in the obese insulin-sensitive subjects when compared with nonobese insulin-sensitive subjects.
CONCLUSIONS In contrast to obese insulin-resistant subjects, metabolically healthy obese individuals are less common than previously thought and do not show increased all-cause, cancer, and CVD mortality risks in a 15-year follow-up study.
The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
- Received April 9, 2010.
- Accepted October 4, 2010.
- © 2011 by the American Diabetes Association.
Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. See http://creativecommons.org/licenses/by-nc-nd/3.0/ for details.