Early-Onset Insulin-Resistant Diabetes in Obese Caucasians Has Features of Typical Type 2 Diabetes, but 3 Decades Earlier
- Siobhan McQuaid, MRCPI1,
- Donal J. O’Gorman, MSC1,
- Obada Yousif, MRCPI1,
- Toh Peng Yeow, MRCPI1,
- Yusof Rahman, MRCPI1,
- Declan Gasparro, BSC1,
- Giovanni Pacini, DSC2 and
- John J Nolan, FRCPI1
- 1Metabolic Research Unit, Department of Endocrinology, St. James’s Hospital, Dublin, Ireland
- 2Metabolic Unit, Institute of Biomedical Engineering, National Research Council, Padova, Italy
- Address correspondence and reprint requests to Prof. John J. Nolan, Metabolic Research Unit, Department of Endocrinology, St. James’s Hospital, Dublin 8, Ireland. E-mail: jnolan{at}stjames.ie
Obesity has dramatically increased in Irish adolescents and young adults and is related to changes in physical activity and diet (1,2). Severe obesity is associated with a much earlier presentation of type 2 diabetes (3—6), as noted in Irish Caucasian patients (7). Most studies of early-onset type 2 diabetes have been in minority populations with higher risk of type 2 diabetes than Caucasians (4—6). The potential for diabetes complications in these young individuals has immediate implications for diagnosis and treatment and longer-term implications for public health. We measured insulin resistance, insulin secretion, and a range of cardiovascular risk markers in an obese group of young Irish subjects with type 2 diabetes and compared them with a matched group of obese nondiabetic subjects and a representative group of older subjects with type 2 diabetes. All of the subjects were from the same clinic, and all were matched for obesity and duration of diabetes.
RESEARCH DESIGN AND METHODS
Eleven subjects with early-onset (age <25 years) and 14 subjects with typical-onset (age >40 years) type 2 diabetes were recruited, as well as 13 nondiabetic control subjects who were age and obesity matched to the young type 2 diabetic group. The protocol had ethical approval, and written informed consent was obtained. An oral glucose tolerance test was used to confirm glucose tolerance.
Intravenous glucose tolerance test
An insulin-modified frequently sampled intravenous glucose tolerance test was performed (8,9). Oral hypoglycemic agents were withheld for 7 days before the …
