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.     

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.     

Pre‐diagnosis cigarette smoking and overall survival in non‐Hodgkin lymphoma

We examined whether smoking prior to non‐Hodgkin lymphoma (NHL) diagnosis was associated with overall survival (OS) and conducted a meta‐analysis to assess the evidence relating pre‐diagnosis cigarette smoking with OS. Among 523 NHL patients, worse OS was suggested for greater pre‐diagnostic smoking habits when compared to never smokers. In the meta‐analysis (n = 5 patient populations), inferior OS was observed for greater number of cigarettes smoked per day, years of cigarette smoking, and pack‐years of cigarette smoking. The inferior survival was more pronounced for follicular than for diffuse large B cell lymphoma. Pre‐diagnosis cigarette smoking may adversely impact the survival of NHL patients.     

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.     

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.     

Obesity and C‐reactive protein in various populations: a systematic review and meta‐analysis

Obesity has been associated with elevated levels of C‐reactive protein (CRP), a marker of inflammation and predictor of cardiovascular risk. The objective of this systematic review and meta‐analysis was to estimate the associations between obesity and CRP according to sex, ethnicity and age. MEDLINE and EMBASE databases were searched through October 2011. Data from 51 cross‐sectional studies that used body mass index (BMI), waist circumference (WC) or waist‐to‐hip ratio (WHR) as measure of obesity were independently extracted by two reviewers and aggregated using random‐effects models. The Pearson correlation (r) for BMI and ln(CRP) was 0.36 (95% confidence interval [CI], 0.30–0.42) in adults and 0.37 (CI, 0.31–0.43) in children. In adults, r for BMI and ln(CRP) was greater in women than men by 0.24 (CI, 0.09–0.37), and greater in North Americans/Europeans than Asians by 0.15 (CI, 0–0.28), on average. In North American/European children, the sex difference in r for BMI and ln(CRP) was 0.01 (CI, ?0.08 to 0.06). Although limited to anthropometric measures, we found similar results when WC and WHR were used in the analyses. Obesity is associated with elevated levels of CRP and the association is stronger in women and North Americans/Europeans. The sex difference only emerges in adulthood.     

Long‐term effect of interferon treatment on the progression of chronic hepatitis B: Bayesian meta‐analysis and meta‐regression

Aim: The long‐term effects of interferon treatment on the progression of chronic hepatitis B (CHB) have been studied extensively, but its true clinical benefits and the predictors of its efficacy remain unclear. Methods: A systematic published work search was undertaken. Eligible studies included those with interferon treatment and control groups, and with liver cirrhosis (LC), hepatocellular carcinoma (HCC) or death as main outcomes. Bayesian meta‐analysis and meta‐regression were performed to assess associations between interferon treatment and disease progression, and the impacts of potential covariates. Results: Eleven articles met the inclusion criteria. LC, HCC and death were end‐points in four, nine and six studies, respectively. In all studies, interferon was associated with significant preventive effects on HCC according to the DerSimonian–Laird method (relative risk [RR] = 0.470, 95% confidence interval [CI] = 0.260–0.850) and Bayesian method adjusting underlying risk (RR = 0.249, 95% Bayesian credible intervals [BCI] = 0.049–0.961), but not according to Bayesian meta‐analysis (RR = 0.274, 95% BCI = 0.059–1.031); and it showed similar effects in death but not in LC. However, most of the high‐quality studies never revealed protective benefits in these end‐points. Bayesian meta‐regression identified Asian ethnicity in death, higher hepatitis B e‐antigen (HBeAg) seroconversion rate or positivity rate, and length of follow up (≤5 years) in HCC as potentially protective against disease progression. Subgroup analysis confirmed similar effects from these factors in HCC and death. Conclusion: Additional evidence is needed to support the role of interferon in delaying CHB progression.     

Long‐chain polyunsaturated fatty acid status in obesity: a systematic review and meta‐analysis

Long‐chain polyunsaturated fatty acid (LCPUFA) status has recently been related to the pathogenesis of obesity. Our aims were to systematically review observational studies investigating LCPUFA status from different blood compartments in overweight or obese subjects and to assess the relationship between LCPUFA profile and obesity. The Ovid MEDLINE, Scopus and Cochrane Library CENTRAL databases were searched from inception to January 2014. The meta‐analysis showed significant differences in the LCPUFA composition of total plasma lipids, plasma phospholipids and plasma cholesteryl esters between overweight or obese subjects and controls. Dihomo‐γ‐linolenic acid (DGLA) values were significantly higher in overweight or obese subjects compared with controls in all the investigated biomarkers. In addition, the DGLA/linoleic acid ratio (surrogate parameter for Δ6 desaturase activity) in plasma phospholipids was significantly elevated (mean difference [MD]: 0.05; 95% confidence interval [CI]: 0.02, 0.08; n = 280), while the arachidonic acid/DGLA ratio (surrogate parameter for Δ5 desaturase activity) was significantly decreased (MD: ?0.55; 95% CI: ?0.71, ?0.39; n = 347) in overweight or obese subjects compared with controls. The results of the present meta‐analysis confirm that LCPUFA profile is altered in obesity and suggest that the differences observed in desaturase activities may be responsible for the disturbed LCPUFA metabolism in obesity.     

Adjuvant chemotherapy versus surgery alone for esophageal squamous cell carcinoma: a meta‐analysis of randomized controlled trials and nonrandomized studies

The effect of adjuvant chemotherapy on survival of patients with thoracic esophageal squamous cell carcinomas is still controversial, and the subgroup of patients who will most likely benefit from the adjuvant chemotherapy on long‐term survival has not yet been identified clearly. Studies published from 1995 to May 2012 were searched in Medline, Embase, PubMed, Cancerlit, the Cochrane Library, CNKI and major scientific meetings. Randomized controlled trials and nonrandomized studies comparing surgery plus adjuvant chemotherapy with surgery alone in patients with resectable thoracic esophageal squamous cell carcinomas were included. Eleven studies with a total of 2047 patients were identified, consisting of the adjuvant chemotherapy arm (n = 887) and surgery‐alone arm (n = 1160). There was not statistically significant benefit on 3‐year overall survival for adjuvant chemotherapy (risk ratio [RR] = 0.89, 95% confidence interval [CI], 0.72 to 1.09; P = 0.25). Adjuvant chemotherapy could significantly prolong the 1‐year disease‐free survival (DFS) (RR = 0.68, 95%CI, 0.51 to 0.89; P = 0.006), but not 3‐year DFS (RR = 0.97, 95%CI, 0.73 to 1.29; P = 0.84). Further analysis showed that patients with stage III‐IV diseases could benefit from adjuvant chemotherapy on 3‐year overall survival (RR = 0.43, 95%CI, 0.31 to 0.61; P = 0.00001), but not in the case of patients with stageI‐IIdiseases (RR = 1.12, 95%CI, 0.65 to 1.93; P = 0.68). Additionally, patients with positive lymph node could benefit on 5‐year DFS from adjuvant chemotherapy (RR = 0.79, 95%CI, 0.64 to 0.99; P = 0.04). The modality treatment with adjuvant chemotherapy for patients with squamous cell carcinoma of thoracic esophagus might be determined according to pathological stage or the status of lymph node metastasis.