Retinopathy Predicts Heart Failure
Middle-aged people with retinopathy are twice as likely to develop heart failure as those without retinopathy, even in the absence of diabetes, hypertension, coronary disease, and other risk factors.
Noting that the retinal circulation reveals systemic microvascular disease, Tien Y. Wong, M.D., of the University of Melbourne's Centre for Eye Research, and associates examined the relationship between heart failure and signs of retinopathy including microaneurysms, retinal hemorrhages, and soft exudates (cotton-wool spots). They used data including retinal photographs from a population-based study of 11,612 subjects aged 49–73 years living in four diverse U.S. communities.
Over a mean follow-up of 6.2 years, heart failure developed in 15.1% of subjects with retinopathy and 4.8% of those without retinal lesions. This risk for developing heart failure remained high after the data were adjusted for CHD, blood pressure, blood glucose level, and smoking; it persisted in both men and women and across all ethnic groups (JAMA 2005;293:63–9).
The findings suggest that systemic microvascular disease plays a role in the pathogenesis of heart failure and that ophthalmologic exams may help assess risk. The results also suggest that the microcirculation should be targeted in efforts to reduce cardiovascular disease. Antihypertensive agents such as ACE inhibitors should be considered because they affect microvessel structure in addition to lowering blood pressure.
Statins Don't Raise Cancer Risk
The longest follow-up of patients randomly assigned to receive either statin therapy or placebo has shown that the drugs do not raise cancer incidence or cancer mortality, said Timo E. Strandberg, M.D., of Kuopio (Finland) University, and associates.
“Most statin trials, which generally last 5–6 years, have not shown any rise in cancer incidence in statin-treated participants, but in two studies some excess of cancer was reported,” Dr. Strandberg and associates said. They examined cancer risk by extending the follow-up in their trial of more than 4,000 subjects in five Nordic countries (Lancet 2004;364:771–7).
During 10 years of follow-up, 100 subjects who had received placebo and 85 who had received simvastatin died from cancer, reflecting a slight but statistically insignificant reduction in cancer mortality with statin use. Similarly, the risk of developing cancer was 12% lower in the statin group than in the placebo group, a nonsignificant difference.
Detox Drug Affects QT Interval
The alpha-2 agonist lofexidine, used with methadone for opioid detoxification, induced QT prolongation in a subject enrolled in a study of the safety of the drug as a daily therapy, reported John Schmittner, M.D., and his associates at the National Institute on Drug Abuse, Baltimore.
Lofexidine has not previously produced ECG changes in human studies, but in animal studies, it has prolonged the QT interval at high doses. In the present case, a 44-year-old woman had a normal QT/QTc of 428/449 ms while taking methadone alone. She became hypotensive, bradycardic, and drowsy after her first dose of lofexidine, and her QT/QTc increased to 612/601 ms. The drug was discontinued, and her QT interval returned to normal within 24 hours (Br. Med. J. 2004;329:1075).
Britannia Pharmaceuticals, the manufacturer of lofexidine (BritLofex), has added a warning about adverse ECG changes to its summary of product characteristics. “Before initiating lofexidine, clinicians may want to screen patients who might be at risk for repolarization abnormalities,” the researchers noted.
'Fetal Origin' Hypothesis Discounted
Impaired growth of the fetus does not increase cholesterol levels in adulthood appreciably, said Rachel Huxley, D.Phil., of the University of Sydney, and her colleagues.
Proponents of the “fetal origin” hypothesis hold that fetal undernutrition is linked to coronary heart disease and related conditions. But it can be argued that there were methodologic flaws in the collection and interpretation of data supporting the hypothesis. Dr. Huxley and her associates conducted a systematic review of 79 relevant studies involving 74,122 subjects, including 25 studies involving more than 45,000 subjects that were never included in previous examinations of this issue.
For every 1-kg decrease in birth weight, there is a 2.0-mg/dL rise in cholesterol in later life, which they characterized as a weak link unlikely to affect public health. “Assuming that nutritional intervention in pregnancy could increase birth weight by as much as 100 g, this association would translate into only approximately 0.19 mg/dL lower total cholesterol level,” which would reduce coronary disease risk by less than 0.025%. In contrast, dietary intervention in adulthood can reduce cholesterol level by 15 mg/dL, for a 15% lower CHD risk, they said (JAMA 2004;292:2755–64).