Genetic screening is no better than assessing traditional risk factors for predicting type-2 diabetes, according to US research.
The findings suggest that GPs should continue to measureBP, weight and glucose levels, at least until additional risk genes for diabetes are discovered.
Previous studies have so far identified 18 gene variants that appear to increase the risk of type-2 diabetes.
For this study, the researchers investigated the effectiveness of genetic screening compared with traditional screening.
Genotyping for the 18 genetic variants was performed on blood samples taken from 2,377 participants, aged 28-62, who did not have diabetes.
Each participant was assigned a genotype score, based on the number of risk-associated gene copies inherited. The scores were then compared with traditional risk factors for diabetes such as BP, BMI, glucose levels and family history.
Overall, 255 cases of diabetes were identified during the follow-up period of 28 years.
The average genotype score was 17.7 among participants who developed diabetes and 17.1 among those who did not develop diabetes.
The researchers concluded that the ability of the genotype score to discriminate those who did not have diabetes from those who did was not significantly better than risk factors.
Lead researcher Dr James Meigs, from the centre for human genetic research and diabetes at Massachusetts General Hospital in Boston, said: 'As additional risk genes are discovered, the value of genetic screening is likely to improve.
'But with our current knowledge, the measurements your physician makes in a standard check-up tell you what you need to know about your type-2 diabetes risk, and genetics doesn't tell you much more.'
- NEJM 2008; 359: 2,208-19.
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