Medicine has long sought to match diagnostic and treatment approaches to the particular needs and risks of individual patients. The decreasing cost and increasing ease of genetic sequencing have propelled the rise of precision medicine. Precision medicine aims to use genetic and other information to provide care tailored to the individual patient, with the goal of improving clinical outcomes and minimizing unnecessary diagnostic and therapeutic interventions. Although developments in genetic sequencing have the potential to transform clinical care, there are important limitations, including uncertainty in the clinical interpretation of many genetic variants and concerns about privacy, discrimination, and cost. To help clinicians understand the basics of genetic sequencing and how to apply it in clinical practice, Annals of Internal Medicine is launching a new "Precision Medicine" series. This introduction provides a general overview of clinical sequencing, with a focus on germline variation. Subsequent articles will use a case-based format to provide concise summaries of specific clinical precision medicine scenarios that are relevant to the practice of internal medicine. These cases will highlight specific clinical indications; interpretation of genetic test results; and ethical, legal, cost, and privacy issues related to genetic testing. The goal is to provide practical information on the appropriate application and interpretation of genomics in routine clinical practice.
Summary Background Results of intervention studies in patients with type 2 diabetes have led to concerns about the safety of aiming for normal blood glucose concentrations. We assessed survival as a function of HbA1c in people with type 2 diabetes. Methods Two cohorts of patients aged 50 years and older with type 2 diabetes were generated from the UK General Practice Research Database from November 1986 to November 2008. We identified 27 965 patients whose treatment had been intensified from oral monotherapy to combination therapy with oral blood-glucose lowering agents, and 20 005 who had changed to regimens that included insulin. Those with diabetes secondary to other causes were excluded. All-cause mortality was the primary outcome. Age, sex, smoking status, cholesterol, cardiovascular risk, and general morbidity were identified as important confounding factors, and Cox survival models were adjusted for these factors accordingly. Findings For combined cohorts, compared with the glycated haemoglobin (HbA1c ) decile with the lowest hazard (median HbA1c 7·5%, IQR 7·5–7·6%), the adjusted hazard ratio (HR) of all-cause mortality in the lowest HbA1c decile (6·4%, 6·1–6·6) was 1·52 (95% CI 1·32–1·76), and in the highest HbA1c decile (median 10·5%, IQR 10·1–11·2%) was 1·79 (95% CI 1·56–2·06). Results showed a general U-shaped association, with the lowest HR at an HbA1c of about 7·5%. HR for all-cause mortality in people given insulin-based regimens (2834 deaths) versus those given combination oral agents (2035) was 1·49 (95% CI 1·39–1·59). Interpretation Low and high mean HbA1c values were associated with increased all-cause mortality and cardiac events. If confirmed, diabetes guidelines might need revision to include a minimum HbA1c value. Funding Eli Lilly and Company.
Summary Background Vitamin D was used to treat tuberculosis in the pre-antibiotic era, and its metabolites induce antimycobacterial immunity in vitro. Clinical trials investigating the effect of adjunctive vitamin D on sputum culture conversion are absent. Methods We undertook a multicentre randomised controlled trial of adjunctive vitamin D in adults with sputum smear-positive pulmonary tuberculosis in London, UK. 146 patients were allocated to receive 2·5 mg vitamin D3 or placebo at baseline and 14, 28, and 42 days after starting standard tuberculosis treatment. The primary endpoint was time from initiation of antimicrobial treatment to sputum culture conversion. Patients were genotyped for Taq I and Fok I polymorphisms of the vitamin D receptor, and interaction analyses were done to assess the influence of the vitamin D receptor genotype on response to vitamin D3 . This trial is registered with ClinicalTrials.gov number NCT00419068. Findings 126 patients were included in the primary efficacy analysis (62 assigned to intervention, 64 assigned to placebo). Median time to sputum culture conversion was 36·0 days in the intervention group and 43·5 days in the placebo group (adjusted hazard ratio 1·39, 95% CI 0·90–2·16; p=0.14). Taq I genotype modified the effect of vitamin D supplementation on time to sputum culture conversion (pinteraction =0·03), with enhanced response seen only in patients with the tt genotype (8·09, 95% CI 1·36–48·01; p=0·02). Fok I genotype did not modify the effect of vitamin D supplementation (pinteraction =0·85). Mean serum 25-hydroxyvitamin D concentration at 56 days was 101·4 nmol/L in the intervention group and 22·8 nmol/L in the placebo group (95% CI for difference 68·6–88·2; p<0·0001). Interpretation Administration of four doses of 2·5 mg vitamin D3 increased serum 25-hydroxyvitamin D concentrations in patients receiving intensive-phase treatment for pulmonary tuberculosis. Vitamin D did not significantly affect time to sputum culture conversion in the whole study population, but it did significantly hasten sputum culture conversion in participants with the tt genotype of the TaqI vitamin D receptor polymorphism. Funding British Lung Foundation.
Summary Background Immunisation of patients with Alzheimer's disease with full-length amyloid-β peptide (Aβ42 ) can clear amyloid plaques from the brain. Our aim was to assess the relation between Aβ42 immune response, degree of plaque removal, and long-term clinical outcomes. Methods In June, 2003, consent for long-term clinical follow-up, post-mortem neuropathological examination, or both, was sought from 80 patients (or their carers) who had entered a phase I randomised, placebo-controlled trial of immunisation with Aβ42 (AN1792, Elan Pharmaceuticals) in September, 2000. The follow-up study was completed in September, 2006. Plaques were assessed in terms of the percentage area of the cortex with Aβ immunostaining (Aβ load) and in terms of characteristic histological features reflecting plaque removal. Survival of all 80 individuals until severe dementia or death was assessed with a Cox proportional hazard model. Findings 20 participants—15 in the AN1792 group, five in the placebo group—died before follow-up started. A further 22 patients—19 in the AN1792 group, three in the placebo group—died during follow-up. Nine of the deceased patients, all in the AN1792 group, had given consent for post-mortem analysis; one of these who did not die with Alzheimer's disease was excluded. In the remaining eight participants who received immunisation and who were examined neuropathologically, mean Aβ load was lower than in an unimmunised control group that was matched for age at death (2·1% [SE 0·7] in treated participants vs 5·1% [0·9] in controls; mean difference 3·0%, 95% CI 0·6–5·4; p=0·02). Although there was considerable variation in Aβ load and degree of plaque removal among immunised participants, the degree of plaque removal varied significantly with mean antibody response attained during the treatment study period (Kruskal-Wallis p=0·02). Seven of the eight immunised patients who underwent post-mortem assessment, including those with virtually complete plaque removal, had severe end stage dementia before death. In the whole cohort, there was no evidence of improved survival (hazard ratio 0·93, 95% CI 0·43–3·11; p=0·86) or of an improvement in the time to severe dementia (1·18, 0·45–3·11; p=0·73) in the AN1792 group versus the placebo group. Interpretation Although immunisation with Aβ42 resulted in clearance of amyloid plaques in patients with Alzheimer's disease, this clearance did not prevent progressive neurodegeneration. Funding Alzheimer's Research Trust, Medical Research Council.
Over the past 75 years, many medical and surgical specialties have emerged. In this Sounding Board article, the authors outline the history of medical and surgical specialization and subspecialization and frame the issues faced by the public and the profession. At a time when most authorities believe that the country desperately needs more generalists, the American Board of Internal Medicine (ABIM) is adding new subspecialties. Specifically, in the past 2 years the ABIM has launched certification in the fields of hospice and palliative care and advanced heart failure and has begun a process for internal-medicine certification with a focused practice in hospital medicine. The ABIM has also approved the subspecialty of adult congenital heart disease to move forward to the American Board of Medical Specialties (ABMS) for final approval. In addition, the ABIM has received requests from specialty societies to . . .
To the Editor: Do duty-hour restrictions for residents improve patient care and residents’ well-being? These are questions that the iCOMPARE (Individualized Comparative Effectiveness of Models Optimizing Patient Safety and Resident Education) trial involving medicine residents (April 19 issue) 1 and the FIRST (Flexibility in Duty Hour Requirements for Surgical Trainees) trial involving surgery residents 2 sought to answer. Medicine residents in programs with flexible duty-hour policies (typically synonymous with longer shifts) reported lower levels of satisfaction with educational quality and well-being than residents in programs with standard duty-hour policies, whereas surgery residents in flexible duty-hour programs reported higher levels of satisfaction with . . .