Adiposity and risk of thyroid cancer: a systematic review and meta‐analysis

Thyroid cancer incidence has increased rapidly over time, as has obesity prevalence. A link between the two appears plausible, but the relation of adiposity to thyroid cancer remains incompletely understood. We performed a meta‐analysis of adiposity measures and thyroid cancer using studies identified through October 2014. Twenty‐one articles yielded data on 12,199 thyroid cancer cases. We found a statistically significant 25% greater risk of thyroid cancer in overweight individuals and a 55% greater thyroid cancer risk in obese individuals as compared with their normal‐weight peers. Each 5‐unit increase in body mass index (BMI), 5 kg increase in weight, 5 cm increase in waist or hip circumference and 0.1‐unit increase in waist‐to‐hip ratio were associated with 30%, 5%, 5% and 14% greater risks of thyroid cancer, respectively. When evaluated by histologic type, obesity was significantly positively related to papillary, follicular and anaplastic thyroid cancers, whereas it revealed an inverse association with medullary thyroid cancer. Both general and abdominal adiposity are positively associated with thyroid cancer. However, relations with BMI vary importantly by tumour histologic type.     

Simple tests for the diagnosis of childhood obesity: a systematic review and meta‐analysis

There is a need to accurately quantify levels of adiposity in order to identify overweight and obesity in children. This systematic review aimed to identify all diagnostic accuracy studies evaluating simple tests for obesity and adiposity, including body mass index (BMI), skin‐fold thickness and waist circumference, compared against high‐quality reference tests. Twenty‐four cohort studies including 25,807 children were included. BMI had good performance when diagnosing obesity: a sensitivity of 81.9% (95% confidence interval [CI]: 73.0 to 93.8) for a specificity of 96.0% (95% CI: 93.8 to 98.1). It was less effective at diagnosing overweight (sensitivity: 76.3%, 95% CI: 70.2 to 82.4; specificity: 92.1% 95% CI: 90.0 to 94.3). When diagnosing obesity, waist circumference had similar performance (sensitivity: 83.8%; specificity: 96.5%). Skin‐fold thickness had slightly poorer performance (sensitivity: 72.5%; specificity: 93.7%). Few studies considered any other tests. There was no conclusive evidence that any test was generally superior to the others. BMI is a good simple diagnostic test for identifying childhood adiposity. It identifies most genuinely obese and adipose children while misclassifying only a small number as obese. There was no conclusive evidence that any test should be preferred to BMI, and the extra complexity of skin‐fold thickness tests does not appear to improve diagnostic accuracy.     

Childhood obesity as a predictor of morbidity in adulthood: a systematic review and meta‐analysis

Obese children are at higher risk of being obese as adults, and adult obesity is associated with an increased risk of morbidity. This systematic review and meta‐analysis investigates the ability of childhood body mass index (BMI) to predict obesity‐related morbidities in adulthood. Thirty‐seven studies were included. High childhood BMI was associated with an increased incidence of adult diabetes (OR 1.70; 95% CI 1.30–2.22), coronary heart disease (CHD) (OR 1.20; 95% CI 1.10–1.31) and a range of cancers, but not stroke or breast cancer. The accuracy of childhood BMI when predicting any adult morbidity was low. Only 31% of future diabetes and 22% of future hypertension and CHD occurred in children aged 12 or over classified as being overweight or obese. Only 20% of all adult cancers occurred in children classified as being overweight or obese. Childhood obesity is associated with moderately increased risks of adult obesity‐related morbidity, but the increase in risk is not large enough for childhood BMI to be a good predictor of the incidence of adult morbidities. This is because the majority of adult obesity‐related morbidity occurs in adults who were of healthy weight in childhood. Therefore, targeting obesity reduction solely at obese or overweight children may not substantially reduce the overall burden of obesity‐related disease in adulthood.     

Intelligence in relation to obesity: a systematic review and meta‐analysis

We performed a systematic review describing obesity/intelligent quotient (IQ) association, particularly childhood IQ in relation to adulthood obesity. After screening 883 citations from five electronic databases, we included 26 studies, most of medium quality. The weighted mean difference (WMD) of the full IQ (FIQ)/obesity association in the pre‐school children was ?15.1 (P > 0.05). Compared with controls, the WMD of FIQ and performance IQ of obese children were ?2.8 and ?10.0, respectively (P < 0.05), and the WMD of verbal IQ was ?7.01 (P > 0.05). With increasing obesity, the FIQ in pre‐school children declined, with a significant difference for severely obese children and FIQ. In pubertal children, a slightly different effect of FIQ and obesity emerged. Two studies reported an inverse FIQ/obesity association in adults, but it was non‐significant after adjusting for educational attainment. Four papers found that childhood FIQ was inversely associated with adult body mass index, but after adjusting for education, became null. Overall there was an inverse FIQ/obesity association, except in pre‐school children. However, after adjusting for educational attainment, FIQ/obesity association was not significantly different. A lower FIQ in childhood was associated with obesity in later adulthood perhaps with educational level mediating the persistence of obesity in later life.     

Emotional processing in obesity: a systematic review and exploratory meta‐analysis

The role of emotional functioning in the development and maintenance of obesity has been investigated, but the literature is poorly integrated. A systematic review and meta‐analysis was performed to explore emotional processing impairments in obesity. PubMed, Web of Knowledge and PsycINFO databases were searched in March 2016, yielding 31 studies comparing emotional processing competencies in individuals with obesity, with or without binge eating disorder (BED), and control groups. Meta‐analyses demonstrated that individuals with obesity had higher scores of alexithymia (d = 0.53), difficulty in identifying feelings (d = 0.34) and externally oriented thinking style (d = 0.31), when compared with control groups. On other competencies, patients with obesity, especially those with comorbid BED, reported lower levels of emotional awareness and difficulty in using emotion regulation strategies, namely, reduced cognitive reappraisal and acceptance, and greater suppression of expression. No evidence of impaired ability to recognize emotions in others or verbally express emotions was found. A general emotion‐processing deficit in obesity was not supported. Instead, an emotional avoidance style may occur modulating later responses of emotion regulation. Additional research is needed to extend the comprehension of these conclusions and the role of BED in emotional functioning in obesity.     

Glucocorticoid‐induced hyperglycaemia in respiratory disease: a systematic review and meta‐analysis

The relative risk of glucocorticoid‐induced hyperglycaemia is poorly quantified. We undertook a meta‐analysis to estimate the association between glucocorticoid treatment and hyperglycaemia, overall and separately in individuals with and without diabetes and underlying respiratory disease. We searched electronic databases for clinical trials of adults randomized to either glucocorticoid treatment or placebo. Eight articles comprising 2121 participants were identified. We performed a random effects meta‐analysis to determine relative risks for the associations between glucocorticoid use and both hyperglycaemia and starting hypoglycaemic therapy. In all individuals, the relative risk of hyperglycaemia comparing glucocorticoid treatment with placebo was 1.72 [95% confidence interval (CI) 1.50‐2.04; p < .001]. The relative risks in individuals with and those without diabetes were 2.10 (95% CI 0.92‐5.02; p = .079) and 1.50 (95% CI 0.79‐2.86; p = .22), respectively. In all individuals, the relative risk of hyperglycaemia requiring initiation of hypoglycaemic therapy, comparing glucocorticoid treatment with placebo, was 1.73 (95% CI 1.40‐2.14; p < .001). In conclusion, glucocorticoid therapy increases the risk of hyperglycaemia in all individuals with underlying respiratory disease but not when diabetic status is analysed separately.     

Ruxolitinib‐associated infections: A systematic review and meta‐analysis

Ruxolitinib exerts immunosuppressive activity that may increase the risk of infectious complications. We performed a systematic review of the literature with the aim of estimating the risk of infections in patients treated with ruxolitinib. Studies were identified by electronic search of MEDLINE and EMBASE database. Differences in the incidence of infectious events between ruxolitinib and comparison groups were expressed as odds ratios (ORs) and 95% confidence intervals (95% CI). Five phase III randomized clinical trials (RCTs) (3 phase IIIa with their extended phase and 2 phase IIIb), 6 phase IV studies and 28 case reports were included in this systematic review. Ruxolitinib was associated with a statistically significant increased risk of herpes zoster infection compared to control group in 3 RCTs including patients with polycythemia vera (OR 7.39 [1.33, 41.07]) and in a pooled analysis of the extended phase IIIa RCTs (OR 5.20 [95%CI 1.27, 21.18]). In the larger phase IV post‐marketing study, the incidence of the most frequent infections was 8% for herpes zoster, 6.1% for bronchitis and 6% for urinary tract infections. In the published case reports, the most frequent infections were tuberculosis (N = 10), hepatitis B reactivation (N = 5) and pneumocystis jeroveci infection (N = 2). Evidence is not solid enough to accurately estimate the risk of infection in ruxolitinib‐treated patients. However, published data clearly suggest that the infection risk may be clinically relevant. Well‐designed studies are warranted to evaluate the risk of ruxolitinib‐associated infection, in order to identify the most appropriate antimicrobial prophylactic strategy.