News in brief

Big drop in hep C among people injecting drugs
RESEARCHERS have observed a big drop in hepatitis C virus (HCV) incidence rate in people who inject drugs (PWID) in the past 10 years, from 30.8 per 100 person-years in 1999‒2001 to 7.9 in 2009‒2011. The research, published in the MJA, was based on the Hepatitis C Incidence and Transmission Study – community (HITS-c), an ongoing community-based prospective observational study of HCV-negative PWID, designed to inform future trials of candidate HCV vaccines. The latest study included 129 serologically confirmed HCV antibody-negative PWID enrolled in three Sydney regions in 2009‒2011 and compared with a cohort study of PWID conducted in three sites in NSW a decade earlier. The researchers found risk factors independently associated with incident HCV infection were younger age (under 27 years) and daily or more frequent injecting. They also found that opioid substitution therapy (OST) was protective against HCV seroconversion and associated with a reduced risk of incident infection among those who mainly injected heroin or other opioids. The more recent cohort was slightly older and had been injecting for longer (consistent with a reduction in new initiates to injecting) and had lower rates of injecting risk behaviour compared with the earlier cohort. “The lower HCV incidence observed in HITS-c than in previous studies is consistent with other data sources indicating that the epidemiology of HCV among PWID in Australia is changing”, the study authors wrote. “Declining HCV incidence over the past decade likely reflects a combination of factors, including changes in the drug market and a decline in the rate of initiation to injecting drug use, a decrease in the PWID population and increased [needle and syringe programs] and OST coverage.”

Age and duration of diabetes linked to complications
RESEARCHERS, including from Australia, have found that, in patients with type 2 diabetes, age (or age at diagnosis) and diabetes duration are independently associated with the risk of macrovascular complications and death. However, the large study, published in Diabetologia, also found that only diabetes duration is independently associated with the risk of microvascular complications, and the effects are greatest at younger rather than older ages. The multi-country study included 11 140 patients with type 2 diabetes in which participants were randomly allocated to receive intensive or standard glucose control. The mean age of study participants was 65.8 years, age at diagnosis 57.8 years and diabetes duration 7.9 years. For each 5-year increase in age (or age at diagnosis), the multiple adjusted risks of macrovascular events and all-cause death increased by 33% and 56%, respectively. For each 5-year increase in duration of diabetes, the risks of macrovascular events and all-cause death were increased by 13% and 15%, respectively, when accounting for age, or increased by 49% and 78%, respectively, when accounting for age at diagnosis. The multiple adjusted risk of microvascular events (new or worsening retinopathy and nephropathy) increased by 28% for each 5-year increase in diabetes duration. The authors wrote that the most likely explanation for the findings was that macrovascular events occurred commonly in the general population and were strongly age dependent. “We might thus expect the risk of macrovascular events to be related to age or age at diagnosis of diabetes, with an added risk conferred by duration of diabetes. By contrast, microvascular events occur more commonly in populations with diabetes and the risk of these events might thus be expected to be predominantly related to duration of diabetes”, they wrote. The study found higher on average HbA1c and fasting glucose levels in the younger age groups despite shorter diabetes duration. “Clearly, when type 2 diabetes occurs in younger people, good glycaemic control appears to be less often achieved”, they wrote, saying the results support the need for more intensive surveillance and glycaemic control to prevent major microvascular complications in younger people living with type 2 diabetes.

Benzodiazepines increases Alzheimer risk
A CANADIAN case–control study of elderly people has shown that the risk of Alzheimer disease was increased by up to 51% in those who had used benzodiazepines in the past. The research, published in the BMJ, included 1796 people with a first diagnosis of Alzheimer disease who had been followed up for at least 6 years before diagnosis, matched with 7184 controls on sex, age group and duration of follow-up. During the study period, 894 people with Alzheimer disease (49.8%) and 2873 controls (40.0%) had ever used benzodiazepines. Treatment with benzodiazepines was still active when dementia was diagnosed in 64.8% of cases and 60.6% of controls. While the proportion of cumulative exposures of 6 or fewer months (≤180 prescribed daily doses [PDDs]) did not substantially differ between the groups, long-term use (>180 PDDs or cumulative exposure over 6 months) was markedly more common among people with Alzheimer disease (32.9%) than controls (21.8%). Use of benzodiazepines at any time was significantly associated with an increased risk of Alzheimer disease (adjusted odds ratio 1.51). “Our study reinforces the suspicion of an increased risk of Alzheimer type dementia among benzodiazepine users, particularly long term users, and provides arguments for carefully evaluating the indications for use of this drug class”, the researchers wrote. “Our findings are of major importance for public health, especially considering the prevalence and chronicity of benzodiazepine use in older people and the high and increasing incidence of dementia in developed countries.” They wrote that it was “crucial” to encourage doctors to “carefully balance the benefits and risks when initiating or renewing a treatment with benzodiazepines and related products in older patients”. Although there was a lack of data in younger adults, “the precautionary principle would also support extending that recommendation to them”. An accompanying editorial supported the development of “a structured reproducible approach to the identification and accurate monitoring of the adverse cognitive effects of all drug treatments used by older adults with multiple chronic conditions, particularly by those at risk of Alzheimer’s disease”.

Gastric banding infection warning
AUSTRALIAN researchers have suggested that the advantage in laparoscopic gastric banding of being able to inflate or deflate the band to alter its restrictive effect might provide a possible portal of entry for infection, particularly in the absence of strict aseptic technique. In an article published in Emerging Infectious Diseases, the authors reported 18 cases of infection associated with laparoscopic gastric banding caused by Mycobacterium fortuitum and M. abscessus during 2005–2011. They reviewed positive cultures at the Queensland state reference laboratory or through correspondence with clinicians, and obtained clinical and epidemiologic data to identify 11 cases of M. fortuitum and seven cases of M. abscessus infection, with the portal thought to be the primary site of infection in 10 of these cases. Complications included peritonitis, band erosion, and chronic ulceration at the port site. The mean age of patients was 45 years, 15 (83%) were women and five patients had diabetes. At the time of insertion of the gastric band, the average weight of patients was 133 kg. None of the patients had been treated with glucocorticoids or other immunosuppressant medications. The time between initial insertion of the device and infection varied widely from 21 days to 8 years, with infection occurring within the first 3 months in eight (44%) of the patients. The authors wrote that rapidly growing mycobacteria could infect both the port and band, occurring as either an early perioperative or late infection. Combination antimicrobial therapy was used on the basis of in vitro susceptibilities, and in all cases successful therapy required removal of the device, they wrote.

Statin benefits for high-risk children
A SMALL study has found long-term statin treatment initiated during childhood in patients with familial hypercholesterolaemia (FH) is associated with normalisation of carotid intima-media thickness (IMT) progression. A research letter, published in JAMA, reported on a 10-year follow-up of 214 children aged 8‒18 years who were heterozygous for FH. The children were randomised into a single-centre, 2-year, double-blind, placebo-controlled trial of pravastatin between 1997 and 1999. After the trial, all children received pravastatin (20–40 mg/d) and were followed up until March 2011 along with 95 unaffected siblings. The researchers wrote that follow-up was achieved in 194 (91%) patients with FH, including 163 (84%) still using lipid-lowering medication, and 83 (87%) siblings, all aged 18‒30 years. They found mean carotid IMT was still significantly greater in patients with FH compared with siblings (0.480 mm vs 0.469 mm), but progression of carotid IMT from baseline was similar in both groups. In patients with FH, the age of initiation of statin therapy was significantly associated with carotid IMT. No serious side effects were reported during follow-up. The researchers wrote that although the safety of statin therapy was supported by extensive evidence in adults, in children only short-term safety had been established. They wrote that the low-density lipoprotein levels of patients with FH at follow-up did not meet current treatment standards and carotid IMT was thicker than in unaffected siblings. “More robust lipid-lowering therapy or earlier initiation of statins may be required to completely restore arterial wall morphology and avert cardiovascular events later in life in this high-risk population”, they wrote.

Sibling bullying neglected
VICTIMS of sibling bullying are twice as likely to develop depression by early adulthood and report self-harming within the previous year compared with children not bullied by siblings, according to research published in Pediatrics. The research was part of an ongoing study included 13 988 children to attending assessment clinics, including face-to-face interviews and psychological and physical tests, from age 7 years. At 18 years of age, 3452 participants completed questionnaires used to investigate the main and adjusted association between sibling bullying and depression. The researchers found those who reported that they had experienced sibling bullying were most commonly subject to non-physical bullying such as being called names (23.1%) or being made fun of (15.4%) several times a week, with no differences in type of bullying experienced by boys and girls. Of the 1810 children who reported that they had not been bullied, 6.4% (N = 115) had depression scores in the clinically significant range at 18 years, 9.3% (N = 169) experienced anxiety, and 7.6% (N = 138) had self-harmed in the previous year. Of the 786 children who reported that they had been bullied by a sibling several times a week (55.3% female), depression was reported by 12.3% at age 18 years, self-harm occurred in 14.1%, and anxiety was reported by 16.0%. “There is a growing concern about bullying occurring at school, at work, or by adult partners”, the authors wrote. “In contrast, sibling bullying is neglected by researchers, clinicians, and policymakers.” They wrote that unlike peer groups, “sibling relationships endure throughout development, with little opportunity for victims to escape. Our results suggest that being bullied by siblings may not be a harmless experience in children’s lives but a risk factor for enduring mental health problems”.