Impaired glucose tolerance, low HDL cholesterol and age > 35 were the strongest predictors of developing diabetes in women with gestational diabetes mellitus (GDM), a study from Vienna has found. Commenting on the study, Dr Chris Barclay, GP with an interest in O&G, Suffolk, writes: ' The development of type 2 diabetes appears to be a continuously progressive process which can last for years or even decades. The metabolic stress of pregnancy appears to unmask this tendency temporarily, even though most women will become euglycaemic after delivery. The underlying metabolic disorder for many of these women will however continue to progress. GDM is an independent risk factor for diabetes. The opportunities for timely intervention and prevention here are obvious. Primary care is best placed to offer this help.'

A meta-analysis of prospective cohort studies has shown an association between time spent viewing TV and risk of type 2 diabetes, cardiovascular disease, and all cause mortality.

Diabetes is associated with an increased risk of major coronary events and all cause mortality, however, only early-onset disease appears to confer CHD equivalence, a study in Archives of Internal Medicine concludes. The authors used data from the British Regional Heart Study, a prospective study of cardiovascular disease in men from 24 British towns who underwent screening from 1978 to 1980. Dr Peter Savill, GP Watercress Medical, Medstead, GPwSI Cardiology, Southampton, comments on the study 'The authors conclude from a further analysis of the duration of diabetes that CHD risk in patients with diabetes escalates significantly with time and approaches CHD risk equivalence only when the disease has been present for more than eight years. The reasons for this could be that those patients developing diabetes later in life might be less insulin resistant and have had less exposure to chronic hyperglycaemia. From a practice perspective perhaps we should manage those with a longer history of diabetes as a coronary risk equivalent and those with more recent onset diabetes according to global cardiovascular risk.'

Tight BP control confers no additional benefit with respect to cardiovascular outcomes in patients with diabetes and CAD compared with usual control, a major trial has shown. It may actually worsen outcomes in the long-term. The INVEST study randomly assigned 22,576 patients to two BP lowering regimens starting with verapamil SR or atenolol and adding in an ACEI, thiazide diuretic or both. The main trial results were published in 2003 and showed no difference in cardiac outcomes between the two approaches. This recently published post hoc analysis of the original data categorised 6,400 diabetes patients with established CAD according to the degree of BP control actually achieved. The primary endpoint was a composite of death, MI or stroke. 'The authors conclude that aiming for a systolic BP lower than 130mmHg has no advantages over usual care and indeed could be harmful over the long term in this patient population. Although this was essentially a subgroup analysis the findings are in keeping with other trials such as ACCORD and should prompt us to exercise caution in lowering BP too aggressively in diabetes patients with CAD.'

Drinking coffee appears to lower markers for subclinical inflammation and raise HDL cholesterol levels but does not affect glucose metabolism, a small study has found. The study included 47 habitual coffee drinkers who stopped drinking coffee for one month. The following month, they drank four cups of filtered coffee per day, followed by eight cups of filtered coffee daily in the third month. The participants were otherwise in good health, less than 65 years of age but had an increased risk of diabetes based on a diabetes risk score. The results showed that after two months drinking coffee there were significant decreases in markers of subclinical inflammation, including interleukin-18 and adiponectin, but no increases in levels of C-reactive protein. Total cholesterol levels increased by 12% after the second month of drinking coffee, but there was also a 7% increase in HDL-cholesterol levels.

Patients with diabetes have a three-fold increased risk of progression from mild cognitive impairment to dementia, a primary care study has shown. The longitudinal cohort study recruited 103 participants aged 65 years or above, from practices in South London, who had mild cognitive impairment. Patients were reassessed four years later. Mild cognitive impairment is a term used to describe people with memory impairment on formal testing who are otherwise functioning well and do not meet clinical criteria for dementia. 'This study provides further evidence that diabetes is associated with faster cognitive decline but at the same time offers the hope that, for this group of patients, we may be able to prevent or slow progression of their condition by more rigorous control of their diabetes. Unfortunately, however, no methodologically sound randomised controlled trials have yet been carried out to investigate this possibility.'