Thousands of people face higher health insurance premiums and may unwittingly invalidate their policies if government plans for vascular checks get the green light.

Earlier this month health secretary Alan Johnson proposed a series of health questions and a cholesterol check for all 40 to 74-year-olds.

The Department of Health predicts that the programme would detect at least 25,000 cases of diabetes or kidney disease earlier and prevent 9,500 heart attacks and strokes.

But an industry body, the Association of British Insurers, told HSJ that anyone with an abnormal result would have to reveal this to their insurer. Failure to do so could result in future claims being paid at a lower rate or, in extreme circumstances, invalidated.

The association also warned that plans to offer tests from pharmacies and other community facilities meant patients risked unwittingly failing to disclose information that might affect their claim, if results were not fed back to family doctors.

A spokesman for the association said: “When somebody applies for life protection or a medical insurance policy, they need to disclose pre-existing medical conditions. Because in a number of cases the screening will be carried out by someone other than the patient’s GP, a question arises over how the information is passed between the individual who has carried out the screening and the GP.

“Given that for insurance companies the GP is the sole point of contact when it comes to finding out about pre-existing conditions, if the results of medical tests are not disclosed, there is a potential, because of the lack of provision for sharing information, for accidental non-disclosure incidences to go up.”

A DH spokeswoman said it planned to discuss the issue of vascular checks with the ABI shortly.