Cannabis and blood chemistry
Cannabis can trigger mechanisms that are harmful to blood chemistry, researchers in the US have found. They say that long-term use may lead to MI, psychosis and supine hypertension. The researchers detected elevated apolipoprotein (apo)C-III concentrations in the blood of marijuana users. Excessive apoC-III reduces the breakdown of certain fatty acids in the blood, too many of which can lead to cardiac disorders and decreased blood flow to the cerebral vasculature in the short-term. They suggest that chronic stimulation of hepatic cannabinoid receptors by delta-9 tetrahydrocannabinol, the active ingredient of marijuana, leads to overproduction of apoC-III and a reduction in the breakdown of these fats.
Jayanthi S, Buie S, Moore S et al. Mol Psychiatry 2008; doi: 10.1038/mp.2008.50
MHRA reports on nicorandil
An association between nicorandil and risk of GI ulceration, including perianal ulceration, has been reported by the MHRA. Although mouth ulceration is a long-recognised side-effect, this association has come to light relatively recently. The ulceration is refractory to treatment and requires withdrawal of the drug, which should occur under the supervision of a cardiologist. The MHRA advises that nicorandil treatment should be considered a potential cause in patients presenting with symptoms of GI ulceration. MHRA Drug Safety Update 2008; 1(11): 5
Early intensive insulin for type-2 diabetes
Treating new-onset type-2 diabetes intensively with insulin improves outcomes compared with oral therapy, a study from China suggests. A total of 382 patients aged 25-70 years were randomised to receive continuous subcutaneous insulin infusion (CSII), multiple daily insulin injections (MDI) or oral hypoglycaemics for one year. More patients on insulin achieved target glycaemic control (97.1 per cent for CSII, 95.2 per cent for MDI, 83.5 per cent for oral therapy) in less time (4.0 days for CSII, 5.6 days for MDI, 9.3 days for oral therapy). Remission rate was also higher for insulin treatment (51.1 per cent for CSII, 44.9 per cent for MDI, 26.7 per cent for oral therapy), and beta cell function and acute insulin response improved significantly.
Weng J, Li Y, Xu W et al. Lancet 2008; 371: 1753-60
Smoking and risk of vascular mortality
Most of the excess risk of vascular mortality for women due to smoking is eliminated rapidly on cessation, a prospective observational study has shown. Researchers followed 104,519 women in the Nurses' Health Study from 1980 to 2004. Compared with never-smokers, current smokers had nearly three times the risk of death, but the excess mortality risk for those who stopped smoking fell by 13 per cent over the first five years after quitting, mostly due to reduced vascular disease mortality. Risk for other causes fell more slowly, but by 20 years after quitting, all-cause mortality risk was similar to that of never-smokers. However, past smokers still had slightly raised risks of smoking-related cancers for up to 30 years.
Kenfield SA, Stampfer MJ, Rosner BA, Colditz GA. JAMA 2008; 299: 2037-47
Albumin excretion and hypertension
Healthy individuals with higher levels of albumin excretion, even those who are considered normal, are at increased risk of hypertension. US researchers investigated new-onset hypertension among 2,179 women in the Nurses' Health Study with no hypertension or diabetes at baseline and an albumin/creatinine ratio <25mg/g. Older women (median 65 years) with a ratio in the highest quartile (4.34-24.17mg/g) were 76 per cent more likely to develop hypertension than those with a ratio in the lowest quartile, while younger women (median 44 years) with a ratio in the highest quartile (3.68-23.84mg/g) had a 35 per cent increased risk. The researchers suggest that the definition of 'normal' urinary albumin excretion should be reconsidered.
Forman JP, Fisher ND, Schopick EL, Curhan GC. J Am Soc Nephrol 2008; doi: 10.1681/ASN.2008010038
Vitamin D status linked to MI risk
Low levels of vitamin D are associated with a higher risk of MI among men, a US study has shown. Researchers undertook a prospective nested case-control study among 18,225 men aged 40-75 years, free from diagnosed cardiovascular disease at baseline, when blood samples were collected. Over 10 years, 454 men experienced non-fatal MI or fatal CHD; 900 men were matched for age, date of blood collection and smoking status. After adjustment for factors including BMI and ethnicity, men deficient in 25-hydroxyvitamin D (25(OH)D ≤15 nanogram/mL) were just over twice as likely to experience MI as those with sufficient 25(OH)D (≥30 nanogram/mL).
Giovannucci E, Liu Y, Hollis BW, Rimm EB. Arch Intern Med 2008; 168: 1174-80
Measures to delay the onset of diabetes
Six years of lifestyle intervention based on diet and exercise can prevent or delay diabetes for up to 14 years post-intervention. However, the impact of this on cardiovascular disease and mortality remains unclear, the researchers say. In 1986, 577 adults with impaired glucose tolerance were randomly assigned to a control group or one of three lifestyle interventions (diet, exercise, or diet plus exercise). Intervention lasted six years and participants were followed up in 2006. Compared to controls, combined lifestyle interventions reduced diabetes incidence by 51 per cent during intervention and by 43 per cent over the 20-year study period. Average annual incidence of newly diagnosed diabetes was 7 per cent for intervention participants, 11 per cent for controls. After 20 years, 80 per cent of the intervention group had diabetes, compared with 93 per cent of controls.
Li G, Zhang P, Wang J et al. Lancet 2008; 371: 1783-9
Dance therapy in CHF
Chronic heart failure (CHF) patients could soon be asked to 'face the music and dance'. Researchers randomised 130 patients with stable CHF (NYHA class II and III, LV ejection fraction <40 per cent) to supervised aerobic training three times per week for eight weeks, alternate slow and fast waltzing for 21 minutes, or a non-exercising control group. Waltzing was found to improve functional capacity and endothelium-dependent dilation of the brachial artery, similarly to traditional aerobic exercise. The researchers suggest waltzing could be considered for stable CHF patients, either in combination with aerobic exercise or instead of it.
Belardinelli R, Lacalaprice F, Ventrella C et al. Circ Heart Fail 2008; doi: 10.1161/CIRCHEARTFAILURE.108.765727.