Ecological versus Case-Control Studies for Testing a Linear-No Threshold Dose-Response Relationship

Quantification of the association between selenium and risk of oesophageal adenocarcinoma (OAC) is still conflicting. The purpose of this meta-analysis is to explore the relationship between selenium levels and OAC risk. PubMed and Web of Knowledge were searched for the related articles. Pooled relative risks (RRs) with 95% confidence intervals (CIs) from random effects models were calculated. Sensitivity analysis and publication bias were conducted. Dose–response relationship was assessed by restricted cubic spline and variance-weighted least squares regression analysis. Five articles involving 748 OAC cases were included in this meta-analysis. Pooled results suggest that higher selenium level was not significantly associated with the risk of OAC (summary RRs=1.08, 95% CIs=0.84–1.39, I2=0%). Besides, no significant association was found in case-control studies (summary RRs=1.13, 95% CIs=0.84–1.52, I2=0%) or cohort studies (summary RRs=0.99, 95% CIs=0.55–1.78, I2=32.6%). A linear dose–response relationship was attested that an increase in dietary selenium intake of 10 μg/day is marginally associated with 1% increase in the risk of developing OAC (summary RRs=1.01, 95% CIs=0.99–1.03), but not statistically significant. No publication bias was found. In conclusion, our analysis indicated that a higher selenium level was not significantly associated with the risk of OAC. The relevant further studies are warranted.

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Action of histamine on the rapidly adapting airway receptors in the dog

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y89-242 ◽

1989 ◽

Vol 67 (12) ◽

pp. 1499-1505 ◽

Cited By ~ 7

Author(s):

K. Ravi ◽

K. K. Teo ◽

C. T. Kappagoda

Keyword(s):

Receptor Antagonist ◽

Dose Response ◽

Geometric Mean ◽

Lymphatic Drainage ◽

Threshold Dose ◽

Response Relationship ◽

Dose Response Relationship ◽

Excitatory Effect ◽

Before And After ◽

The Right

The effects of histamine on the activity of rapidly adapting receptors (RAR) of the airways were investigated in anesthetized dogs. With bolus injections given into the right atrium, the threshold dose of histamine required for the excitation of RAR (n = 7) was 0.82 μg/kg (+1.33/−0.51, geometric mean). With increasing doses of histamine, a dose–response relationship was seen in the activity of RAR. Obstruction of the lymphatic drainage from the lungs reduced the threshold dose to histamine (i.e., shifted the dose–response curve to the left significantly). This change in the dose–response relationship was not accompanied by a corresponding change in the relationship of histamine dose to airway pressures recorded before and after lymphatic obstruction. Against a background of pulmonary venous congestion produced by partial obstruction of the mitral valve, subthreshold doses of histamine stimulated the RAR (n = 4). The excitatory effect of histamine on RAR was found to be abolished by the administration of the H1 receptor antagonist diphenhydramine but not by the H2 receptor antagonist cimetidine. Intravenous infusion of histamine (0.4 μg∙kg−1∙min−1) for a period of 10 min increased the RAR activity (n = 6) significantly without producing detectable changes in airway mechanics. The results indicate that contraction of the smooth muscle of the airways may not be a prerequisite for the excitation of RAR, especially at low doses. It is suggested that some of the effects of histamine on RAR are mediated by a local expansion of the extravascular fluid caused by an increase in the permeability of the bronchial vasculature.Key words: histamine, pulmonary congestion, vagal sensory receptors.

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Damp mouldy housing and early childhood hospital admissions for acute respiratory infection: a case control study

Thorax ◽

10.1136/thoraxjnl-2018-212979 ◽

2019 ◽

Vol 74 (9) ◽

pp. 849-857 ◽

Cited By ~ 6

Author(s):

Tristram Ingham ◽

Michael Keall ◽

Bernadette Jones ◽

Daniel R T Aldridge ◽

Anthony C Dowell ◽

...

Keyword(s):

Dose Response ◽

Acute Respiratory Infection ◽

Case Control Study ◽

Quality Measures ◽

Case Control ◽

Housing Quality ◽

Response Relationship ◽

Dose Response Relationship ◽

Unit Increase ◽

Control Study

IntroductionA gap exists in the literature regarding dose–response associations of objectively assessed housing quality measures, particularly dampness and mould, with hospitalisation for acute respiratory infection (ARI) among children.MethodsA prospective, unmatched case–control study was conducted in two paediatric wards and five general practice clinics in Wellington, New Zealand, over winter/spring 2011–2013. Children aged <2 years who were hospitalised for ARI (cases), and either seen in general practice with ARI not requiring admission or for routine immunisation (controls) were included in the study. Objective housing quality was assessed by independent building assessors, with the assessors blinded to outcome status, using the Respiratory Hazard Index (RHI), a 13-item scale of household quality factors, including an 8-item damp–mould subscale. The main outcome was case–control status. Adjusted ORs (aORs) of the association of housing quality measures with case–control status were estimated, along with the population attributable risk of eliminating dampness–mould on hospitalisation for ARI among New Zealand children.Results188 cases and 454 controls were studied. Higher levels of RHI were associated with elevated odds of hospitalisation (OR 1.11/unit increase (95% CI 1.01 to 1.21)), which weakened after adjustment for season, housing tenure, socioeconomic status and crowding (aOR 1.04/unit increase (95% CI 0.94 to 1.15)). The damp–mould index had a significant, adjusted dose–response relationship with ARI admission (aOR 1.15/unit increase (95% CI 1.02 to 1.30)). By addressing these harmful housing exposures, the rate of admission for ARI would be reduced by 19% or 1700 fewer admissions annually.ConclusionsA dose–response relationship exists between housing quality measures, particularly dampness–mould, and young children’s ARI hospitalisation rates. Initiatives to improve housing quality and to reduce dampness–mould would have a large impact on ARI hospitalisation.

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The risk of perchlorate and iodine on the incidence of thyroid tumors and nodular goiter: a case-control study in southeastern China

Environmental Health ◽

10.1186/s12940-021-00818-8 ◽

2022 ◽

Vol 21 (1) ◽

Author(s):

Huirong Wang ◽

Yousheng Jiang ◽

Jiayi Song ◽

Huiwen Liang ◽

Yuan Liu ◽

...

Keyword(s):

Mass Spectrometry ◽

Thyroid Function ◽

Dose Response ◽

Nodular Goiter ◽

Case Control ◽

Thyroid Tumors ◽

Response Relationship ◽

Papillary Thyroid ◽

Dose Response Relationship ◽

Linear Dose

Abstract Background The incidence rates of thyroid tumors and nodular goiter show an upward trend worldwide. There are limited reports on the risk of perchlorate and iodine on thyroid tumors, but evidence from population studies is scarce, and their impact on thyroid function is still uncertain. Therefore, the objective of this study was to investigate the association of perchlorate and iodine with the risk of nodular goiter (NG), papillary thyroid microcarcinoma (PTMC), and papillary thyroid carcinoma (PTC) and to assess the correlation between perchlorate and iodine with thyroid function indicators. Methods A case–control population consisting of 184 pairs of thyroid tumors and nodular goiter matched by gender and age (±2 years) was recruited in this study. Serum and urine samples were collected from each participant. Thyroid function indicators in serum were tested by automatic chemical immunofluorescence, and perchlorate and iodine levels in urine were determined by ultra-high performance liquid chromatography tandem-mass spectrometry and inductively coupled plasma-mass spectrometry, respectively. Conditional logistic regressions and multiple linear regressions were used to analyze the associations. Results Urinary perchlorate concentration was significantly higher in total cases, NG and PTC than in the corresponding controls (P < 0.05). Perchlorate was positively associated with PTC (OR = 1.058, 95% CI: 1.009, 1.110) in a non-linear dose–response relationship, but there was no association between perchlorate and NG or PTMC. Iodine was not associated with the risk of thyroid tumors and NG and did not correlate with the thyroid function indicators. Furthermore, perchlorate showed a positive correlation with thyroid stimulating hormone (TSH) at iodine adequate levels (P < 0.05), and a negative correlation with free triiodothyronine (FT3) and a positive correlation with thyroglobulin antibody (TgAb) at iodine more than adequate or excess levels (P < 0.05). Conclusions Perchlorate can increase the risk of PTC in a non-linear dose–response relationship and disturb the thyroid hormone homeostasis and thyroid autoantibody levels.

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