Knowledge of risk of developing diabetes mellitus among siblings of Type 2 diabetic patients.

AIMS: We set out to investigate the extent to which siblings of diabetic subjects perceived themselves likely to develop Type 2 diabetes mellitus (DM) when offered screening tests.
METHODS: Nondiabetic siblings, aged 35-74 years, of Type 2 diabetic patients who were more than 35 years old at diagnosis had fasting plasma glucose measured in a study to determine heritability of diabetes. Questionnaires assessing perceived likelihood of developing, seriousness and knowledge about diabetes were completed. Logistic regression assessed factors predicting perceptions of diabetes risk.
RESULTS: Factors predicting diabetes on screening were male sex, increasing age and body mass index (BMI) > or = 30. Eighty-nine per cent of 540 eligible siblings completed questionnaires. Thirty-eight per cent saw themselves at increased risk of diabetes and 34% thought diabetes a serious problem. Predictors of perceiving an increased likelihood of developing diabetes were female sex, age 35-54 years vs. 55-74 years and having a parent with diabetes. BMI did not affect perceptions of likelihood.
CONCLUSION: A perception of reduced vulnerability to diabetes may occur due to unawareness of risk or minimization of risk. Feelings of invulnerability may affect emotional response to a subsequent result. It is not known whether providing more information about the risk of developing diabetes prior to screening would affect outcomes