Data on the association between subclinical thyroid dysfunction and coronary heart disease (CHD) and mortality are conflicting. To summarize prospective evidence about the relationship between subclinical thyroid dysfunction and CHD and mortality. MEDLINE (1950 to January 2008) without language restrictions and reference lists of retrieved articles were searched. Two reviewers screened and selected cohort studies that measured thyroid function and then followed persons prospectively to assess CHD or mortality. By using a standardized protocol and forms, 2 reviewers independently abstracted and assessed studies. Ten of 12 identified studies involved population-based cohorts that included 14 449 participants. All 10 population-based cohort studies examined risks associated with subclinical hypothyroidism (2134 CHD events and 2822 deaths), whereas only 5 examined risks associated with subclinical hyperthyroidism (1392 CHD events and 1993 deaths). In a random-effects model, the relative risk (RR) for subclinical hypothyroidism for CHD was 1.20 (95% CI, 0.97 to 1.49; P for heterogeneity = 0.14; I² = 33.4%). Risk estimates were lower when higher-quality studies were pooled (RR, 1.02 to 1.08) and were higher among participants younger than 65 years (RR, 1.51 [CI, 1.09 to 2.09] for studies with mean participant age 0.50; I² = 0% for all studies). Individual studies adjusted for different potential confounders, and 1 study provided only unadjusted data. Publication bias or selective reporting of outcomes could not be excluded. Subclinical hypothyroidism and hyperthyroidism may be associated with a modest increased risk for CHD and mortality, with lower risk estimates when pooling higher-quality studies and larger CIs for subclinical hyperthyroidism.

The tobacco industry’s most recent response to the documented harms of cigarette smoking was to launch new heat-not-burn (HNB) tobacco cigarettes.¹ Philip Morris International (PMI) created IQOS (I-Quit-Ordinary-Smoking): disposable tobacco sticks soaked in propylene glycol, which are inserted in a holder in the HNB cigarette. The tobacco is heated with an electric blade at 350°C. The cigarettes are marketed by PMI as a “revolutionary technology that heats tobacco without burning it, giving you the true taste of tobacco, with no smoke, no ash and less smell.”² In many countries, laws that protect people from passive smoke only apply to smoked tobacco products. Philip Morris International claims that IQOS releases no smoke because the tobacco does not combust and the tobacco leaves are only heated not burned. However, there can be smoke without fire. The harmful components of tobacco cigarette smoke are products of incomplete combustion (pyrolysis) and the degradation of tobacco cigarettes through heat (thermogenic degradation). Complete combustion occurs at a high temperature (>1300°C), higher than the heat generated by smoking a tobacco cigarette (<800°C). Typical markers of pyrolysis and thermogenic degradation of tobacco cigarettes are acetaldehyde, an irritant carcinogenic volatile organic compound, benzo[a]pyrene, a carcinogenic polycyclic aromatic hydrocarbon, and carbon monoxide.

In populations of older adults, prediction of coronary heart disease (CHD) through traditional risk factors is less accurate than among middle-aged adults.¹ Resting electrocardiographic (ECG) abnormalities have been shown to be independently associated with incident CHD and cardiovascular disease (CVD) events,^2-8 and ECG is a good candidate to consider for risk stratification of asymptomatic participants given its low cost, wide use, and safety.^9,10 However, performing routine ECG among asymptomatic adults is not supported by current evidence.¹¹

Clinical question Recent 15-year updates of sigmoidoscopy screening trials provide new evidence on the effectiveness of colorectal cancer screening. Prompted by the new evidence, we asked: “Does colorectal cancer screening make an important difference to health outcomes in individuals initiating screening at age 50 to 79? And which screening option is best?” Current practice Numerous guidelines recommend screening, but vary on recommended test, age and screening frequency. This guideline looks at the evidence and makes recommendations on screening for four screening options: faecal immunochemical test (FIT) every year, FIT every two years, a single sigmoidoscopy, or a single colonoscopy. Recommendations These recommendations apply to adults aged 50-79 years with no prior screening, no symptoms of colorectal cancer, and a life expectancy of at least 15 years. For individuals with an estimated 15-year colorectal cancer risk below 3%, we suggest no screening (weak recommendation). For individuals with an estimated 15-year risk above 3%, we suggest screening with one of the four screening options: FIT every year, FIT every two years, a single sigmoidoscopy, or a single colonoscopy (weak recommendation). With our guidance we publish the linked research, a graphic of the absolute harms and benefits, a clear description of how we reached our value judgments, and linked decision aids. How this guideline was created A guideline panel including patients, clinicians, content experts and methodologists produced these recommendations using GRADE and in adherence with standards for trustworthy guidelines. A linked systematic review of colorectal cancer screening trials and microsimulation modelling were performed to inform the panel of 15-year screening benefits and harms. The panel also reviewed each screening option’s practical issues and burdens. Based on their own experience, the panel estimated the magnitude of benefit typical members of the population would value to opt for screening and used the benefit thresholds to inform their recommendations. The evidence Overall there was substantial uncertainty (low certainty evidence) regarding the 15-year benefits, burdens and harms of screening. Best estimates suggested that all four screening options resulted in similar colorectal cancer mortality reductions. FIT every two years may have little or no effect on cancer incidence over 15 years, while FIT every year, sigmoidoscopy, and colonoscopy may reduce cancer incidence, although for FIT the incidence reduction is small compared with sigmoidoscopy and colonoscopy. Screening related serious gastrointestinal and cardiovascular adverse events are rare. The magnitude of the benefits is dependent on the individual risk, while harms and burdens are less strongly associated with cancer risk. Understanding the recommendation Based on benefits, harms, and burdens of screening, the panel inferred that most informed individuals with a 15-year risk of colorectal cancer of 3% or higher are likely to choose screening, and most individuals with a risk of below 3% are likely to decline screening. Given varying values and preferences, optimal care will require shared decision making.

We aimed to assess the prevalence and management of clinical familial hypercholesterolaemia (FH) among patients with acute coronary syndrome (ACS). We studied 4778 patients with ACS from a multi-centre cohort study in Switzerland. Based on personal and familial history of premature cardiovascular disease and LDL-cholesterol levels, two validated algorithms for diagnosis of clinical FH were used: the Dutch Lipid Clinic Network algorithm to assess possible (score 3–5 points) or probable/definite FH (>5 points), and the Simon Broome Register algorithm to assess possible FH. At the time of hospitalization for ACS, 1.6% had probable/definite FH [95% confidence interval (CI) 1.3–2.0%, n = 78] and 17.8% possible FH (95% CI 16.8–18.9%, n = 852), respectively, according to the Dutch Lipid Clinic algorithm. The Simon Broome algorithm identified 5.4% (95% CI 4.8–6.1%, n = 259) patients with possible FH. Among 1451 young patients with premature ACS, the Dutch Lipid Clinic algorithm identified 70 (4.8%, 95% CI 3.8–6.1%) patients with probable/definite FH, and 684 (47.1%, 95% CI 44.6–49.7%) patients had possible FH. Excluding patients with secondary causes of dyslipidaemia such as alcohol consumption, acute renal failure, or hyperglycaemia did not change prevalence. One year after ACS, among 69 survivors with probable/definite FH and available follow-up information, 64.7% were using high-dose statins, 69.0% had decreased LDL-cholesterol from at least 50, and 4.6% had LDL-cholesterol ≤1.8 mmol/L. A phenotypic diagnosis of possible FH is common in patients hospitalized with ACS, particularly among those with premature ACS. Optimizing long-term lipid treatment of patients with FH after ACS is required.