Tag: statistics

Am J Clin Nutr. 2021 Oct 7:nqab342. doi: 10.1093/ajcn/nqab342. Online ahead of print.

ABSTRACT

BACKGROUND: Recent observational studies have suggested that circulating phosphorus levels are positively associated with risk of prostate cancer. However, little is known about the causal direction of the association.

OBJECTIVE: To explore the potential causal relationship between circulating phosphorus and risk of prostate cancer, we conducted a Mendelian randomization (MR) study.

DESIGN: Summary statistics of prostate cancer were obtained from a meta-analysis of genome-wide association studies (GWAS) consisting of 79,148 cases and 61,106 controls. Single nucleotide polymorphisms (SNP) associated with serum phosphorus level were selected from a GWAS of 291,408 individuals from the UK Biobank. MR analysis was performed using the inverse-variance weighted (IVW) method, supplemented with simple-median, weighted-median, maximum likelihood-based, MR-Egger regression and MR-PRESSO test. We also performed a meta-analysis of observational studies to assess the associations of dietary phosphorus intake and serum phosphorus level with risk of prostate cancer.

RESULTS: In the MR analysis, a total of 125 independent SNPs associated with serum phosphorus levels were used as instrumental variables. Genetically predicted serum phosphorus levels were associated with a 19% increased risk of prostate cancer (95% confidence interval (CI): 9%, 31%) per one SD increment of serum phosphorus by IVW (P = 1.82 × 10-4). Sensitivity analyses using alternative MR methods produced similar positive associations, and no evidence of pleiotropy was detected by MR-Egger regression (P = 0.422). For meta-analysis, eight studies for dietary phosphorus intake and four for serum phosphorus levels were included involving a total of 669,080 participants. Consistently, high dietary phosphorus intake and serum phosphorus levels were associated with an 8% (95% CI: 4%, 12%) and 7% (95% CI: 1%, 14%) increase in prostate cancer risk, respectively.

CONCLUSIONS: Our study suggested a potential causal relationship between circulating phosphorus and risk of prostate cancer. Further studies are warranted to elucidate the underlying mechanism of phosphorus in the development of prostate cancer.

PMID:34617559 | DOI:10.1093/ajcn/nqab342

Am J Clin Nutr. 2021 Oct 7:nqab339. doi: 10.1093/ajcn/nqab339. Online ahead of print.

ABSTRACT

BACKGROUND: Diet and physical activity (PA) are independent risk factors for obesity and chronic diseases including type 2 diabetes mellitus (T2DM) and metabolic syndrome (MetS). The temporal sequence of these exposures may be used to create patterns with relationships to health status indicators.

OBJECTIVES: The objectives were to create clusters of joint temporal dietary and PA patterns (JTDPAPs); determine their association with health status indicators including BMI, waist circumference (WC), fasting plasma glucose, hemoglobin A1c, triglycerides, high-density lipoprotein cholesterol, total cholesterol, blood pressure and disease status including obesity, T2DM, and MetS in United States adults.

DESIGN: A 24-hour dietary recall and random day of accelerometer data of 1836 participants from the cross-sectional NHANES 2003-2006 data were used to create JTDPAPs clusters by constrained dynamic time warping, coupled with kernel k-means clustering algorithm. Multivariate regression models determined associations between the 4 JTDPAP clusters and health and disease status indicators, controlling for potential confounders and adjusting for multiple comparisons.

RESULT: A JTDPAP cluster with proportionally equivalent energy consumed at two main eating occasions reaching up to 1600 and 2200 kcal from 11:00 to 13:00 and 17:00 to 20:00, and the highest PA counts among 4 clusters from 8:00 to 20:00, was associated with significantly lower body mass index (BMI) (P < 0.0001), WC (P = 0.0001), total cholesterol (P = 0.02) and odds of obesity (OR = 0.2, 95% CI: 0.1, 0.5) compared to a JTDPAP cluster with proportionally equivalent energy consumed reaching up to 1600 and 1800 kcal from 11:00 to 14:00 and 17:00 to 21:00, and high PA counts from 9:00 to 12:00.

CONCLUSIONS: The joint temporally patterned sequence of diet and PA can be used to cluster individuals with meaningful associations to BMI, WC, total cholesterol, and obesity. Temporal patterns hold promise for future development of lifestyle patterns that integrate additional temporal and contextual activities.

PMID:34617560 | DOI:10.1093/ajcn/nqab339

Aging Ment Health. 2021 Oct 7:1-9. doi: 10.1080/13607863.2021.1985965. Online ahead of print.

ABSTRACT

OBJECTIVES: In this study, we assess the relationship between food insecurity andperceived stress among older adults (50+) in six low- and middle-income countries of China, Ghana, India, Mexico, Russia and, South Africa.

METHODS: Cross-sectional comparative analysis was conducted using nationally representative data from the WHO’s Study on global AGEing and adult health survey. Bivariate and multivariate regression analyses examine if food insecurity was associated with perceived stress. We also examined the mediating role of health conditions on the association between food insecurity and perceived stress.

RESULTS: Across countries, the mean perceived stress score was higher among the older population with food insecurity. Regression analysis showed significant and positive association between food insecurity and perceived stress. Findings from the pooled data of six countries showed, older adults who experienced severe food insecurity (β = 4.05, p < .001) had higher perceived stress scores. The association was statistically significant in India, Russia, South Africa, and Ghana.

CONCLUSION: Food insecurity showed significant adverse impact on perceived stress among the older population in low- and middle-income countries. Policy measures to reduce household food insecurity are important for improving both mental and physical health conditions of the growing older population in low- and middle-income countries.

PMID:34617495 | DOI:10.1080/13607863.2021.1985965

Ergonomics. 2021 Oct 7:1-37. doi: 10.1080/00140139.2021.1991002. Online ahead of print.

ABSTRACT

Although professional bus drivers are required to perform their task while adopting a prolonged constrained sitting posture, existence of possible effects in terms of postural strategies has been scarcely investigated under actual working conditions. This study aimed to characterize modifications of trunk sway in 14 professional bus drivers during regular shifts performed on non-urban routes using a pressure-sensitive mat placed on the seat. Center-of-pressure (COP) time series were extracted from body-seat pressure data to calculate sway parameters (i.e. sway area, COP path length, COP displacements and velocities). Results show generalized increase in trunk sway as driving progresses, which becomes statistically significant after approximately 70-100 minutes of continuous driving. This may indicate the adoption of specific strategies to cope with discomfort onset or a fatigue-induced alteration of postural features. Trunk sway monitoring of bus drivers may be useful in detecting postural behaviors potentially associated with deteriorating performance and discomfort onset.Practitioner Summary: Professional bus drivers operate in sitting position for prolonged time. Such constrained posture may induce discomfort and fatigue. We investigated trunk sway during actual shifts using pressure-sensitive mats. Significant increase of sway was detected after 70min of continuous driving. Body-seat pressure data could be used as discomfort and fatigue markers.

PMID:34617498 | DOI:10.1080/00140139.2021.1991002

Eur J Ophthalmol. 2021 Oct 7:11206721211048365. doi: 10.1177/11206721211048365. Online ahead of print.

ABSTRACT

PURPOSE: To study the influence of weight reduction after bariatric surgery on the intraocular pressure (IOP), retinal nerve fiber layer (RNFL) thickness, and blood flow of optic nerve head by optical coherence tomography angiography (OCTA).

METHODS: This prospective observational cohort study included 60 obese patients. Body mass index (BMI), IOP, RNFL, and ganglion cell complex (GCC) thickness, rim area, and radial peripapillary capillary (RPC) vessel density were assessed before and 3 months after bariatric surgery.

RESULTS: The BMI and the IOP showed significant postoperative reduction to 40.45 ± 4.3 kg/m² and 14.83 ± 2.5 mmHg while the preoperative results were 51.13 ± 4.83 kg/m² and 16.95 ± 4.2 mm (p < 0.0001), respectively. No statistically significant change was detected in the RNFL, GCC thickness, rim area, or the RPC vessel density (p > 0.05). No statistically significant correlation was detected between the BMI changes and changes in the IOP, RNFL thickness, rim area, GCC thickness, or RPC vessel density.

CONCLUSION: No significant effect of bariatric surgery on the RNFL thickness and the optic nerve head blood flow measured by OCTA despite a significant IOP reduction 3 months post-surgical. OCTA can be a useful tool to assess the short-term influence of significant weight reduction on the retinal microcirculation.

SUMMARY: Despite a significant BMI and IOP reduction following bariatric surgery in obese patients, the vascular flow of the ONH, measured by OCTA, and the RNFL thickness were not significantly affected. The former might be attributed to the complex autoregulatory mechanisms related to the ONH and its microcirculation.

PMID:34617478 | DOI:10.1177/11206721211048365

Urologia. 2021 Oct 7:3915603211049888. doi: 10.1177/03915603211049888. Online ahead of print.

ABSTRACT

BACKGROUND: Studies demonstrate that getting antioxidants in the course of treatment has a positive impact beneficial effect on fertility, especially on the quality of sperm. Because of that reason antioxidants are recommended as a potentially influential treatment for infertility in men. However, it is argued that this treatment is not based on sufficient evidence and has no effect on the rate of healthy pregnancy.

OBJECTIVE: In this study, two different antioxidant combinations with different doses and contents were evaluated in terms of their effect on sperm parameters.

MATERIALS/METHODS: A total of 122 patients diagnosed with idiopathic infertility were enrolled in our multicenter study. The patients were divided into two different groups: The first group used a combination 2 × 1 sachet form (l-carnitine 1 g, acetyl-l-carnitine 0.5 g, fructose 1 g, citric acid 0.50 mg, selenium 50 µg, coenzyme Q10 20 mg, vitamin C 90 mg, zinc 10 mg, folic acid 200 µg, and vitamin B12 1.5 µg) and the second group used a combination tablets form 2 × 1 (l-carnitine 500 mg, selenium 50 µg, coenzyme Q10 20 mg, vitamin C 60 mg, zinc 15 mg, folic acid 400 µg, vitamin E, and ginseng 15 µg) for 6 months. The total semen volume, the total sperm number, sperm concentration, sperm motility, and lastly morphological findings of the patients were compared at the end of 6 months.

RESULTS: The mean age of the patients participating in the study was 30.8 ± 6.05 years. No significant difference was found between the two groups in terms of baseline sperm count. There was a significant difference between the baseline and sixth-month values of the patients using both combinations. However, no significant statistical difference was found between the groups according to the sixth-month data. The combinations of both antioxidants had a positive effect on sperm parameters, and the use of different doses and contents had a similar effect.

CONCLUSION: Both antioxidants respectively had a positive effect on sperm parameters and also the use of different doses and contents had a similar effect.

PMID:34617487 | DOI:10.1177/03915603211049888

Pharm Dev Technol. 2021 Oct 7:1-33. doi: 10.1080/10837450.2021.1990946. Online ahead of print.

ABSTRACT

It is widely accepted that the use of topical sunscreens has medical importance with potential to prevent skin damage by protecting from solar ultraviolet radiation (UVR) effects. Pharmaceutical emulsions require an optimal qualitative and quantitative combination of emollients, emulsifiers and others compounds such as softening agents and, for sunscreens, a combination of chemical and physical UV filters. Herein, we applied the quality by design (QbD) concept to achieve stable and effective compounded sunscreen emulsions. By using the statistical tool of design of experiments, it was possible to identify the influence of emulsifier type (with low and high Hydrophile-Lipophile Balance) and concentrations of emollient and softening agent on the achievement of formulations with suitable organoleptic and physicochemical features. Compounded emulsions with pleasant macroscopic aspects were obtained. Three formulations with physicochemical properties in targeted ranges were selected, namely pH ∼6.0, conductivity >0.0 µS/cm², spreadability factor ∼1-1.5 g/mm², viscosity ∼12000 mPa.s and sunscreen protection factor ∼30. Freeze-thaw cycle and accelerated stability study under different storage conditions allowed selecting a stable emulsion that ensured photoprotection in biological assays. The QbD approach was essential to select the best, low-cost compounded sunscreen emulsion, with targeted physicochemical parameters.

PMID:34617471 | DOI:10.1080/10837450.2021.1990946

Ann Otol Rhinol Laryngol. 2021 Oct 7:34894211050625. doi: 10.1177/00034894211050625. Online ahead of print.

ABSTRACT

OBJECTIVE: To evaluate the impact of otolaryngology programs’ social media on residency candidates in the 2020 to 2021 application cycle.

METHODS: An anonymous survey was distributed via Otomatch, Headmirror, and word of mouth to otolaryngology residency applicants in the 2021 Match. Survey items included demographics, social media usage, and impact of programs’ social media on applicant perception and ranking. Descriptive statistics were performed, and responses based on demographic variables were compared using Fisher’s exact and Mann-Whitney U tests.

RESULTS: Of 64 included respondents, nearly all (61/64, 95%) used Facebook, Instagram, and/or Twitter for personal and/or professional purposes. Applicants (59/64, 92%) most commonly researched otolaryngology residency programs on Instagram (55/59, 93%) and Twitter (36/59, 61%), with younger (P = .023) and female (P = .043) applicants being more likely to engage with programs on Instagram. Program accounts were most helpful in showcasing program culture (50/59, 85%) and highlighting its location (34/59, 58%). Nearly one third (19/59, 32%) reported that social media impacted their rank list. Age, gender, reapplication, home program status, or time taken off before and/or during medical school did not significantly influence social media’s usefulness in the application cycle.

CONCLUSION: Social media platforms like Instagram and Twitter are frequently used by applicants to assess otolaryngology residency programs. Programs’ social media accounts effectively demonstrate program culture and affect applicants’ rank lists. As social media usage continues to rise in the medical community, these findings can help otolaryngology residency programs craft a beneficial online presence that aids in recruitment, networking, and education.

PMID:34617461 | DOI:10.1177/00034894211050625

Biotechniques. 2021 Oct 7. doi: 10.2144/btn-2021-0034. Online ahead of print.

ABSTRACT

We designed and validated a test system that simulates a growth environment for Zea mays L. maize seedlings under conditions of low moisture gradient in darkness. This system allowed us to simultaneously measure mesocotyl elongation and the primary root hydrotropic response in seedlings before the emergence phase in a collection of maize hybrids. We found great variation in these two traits with statistically significant reduction of their elongations under the low moisture gradient condition that indicate the richness of maize genetic diversity. Hence, the objective of designing a new test system that evaluates the association between these underground traits with the potential use to measure other traits in maize seedlings related to early vigor was achieved.

PMID:34617460 | DOI:10.2144/btn-2021-0034

Sci Rep. 2021 Oct 6;11(1):19853. doi: 10.1038/s41598-021-99310-z.

ABSTRACT

Cognitive decline in early-stage Alzheimer’s disease (AD) may depend on genetic variability. In the Swedish BioFINDER study, we used polygenic scores (PGS) (for AD, intelligence, and educational attainment) to predict longitudinal cognitive change (measured by mini-mental state examination (MMSE) [primary outcome] and other cognitive tests) over a mean of 4.2 years. We included 260 β-amyloid (Aβ) negative cognitively unimpaired (CU) individuals, 121 Aβ-positive CU (preclinical AD), 50 Aβ-negative mild cognitive impairment (MCI) patients, and 127 Aβ-positive MCI patients (prodromal AD). Statistical significance was determined at Bonferroni corrected p value < 0.05. The PGS for intelligence (beta = 0.1, p = 2.9e-02) was protective against decline in MMSE in CU and MCI participants regardless of Aβ status. The polygenic risk score for AD (beta = – 0.12, p = 9.4e-03) was correlated with the rate of change in MMSE and was partially mediated by Aβ-pathology (mediation effect 20%). There was no effect of education PGS on cognitive measures. Genetic variants associated with intelligence mitigate cognitive decline independent of Aβ-pathology, while effects of genetic variants associated with AD are partly mediated by Aβ-pathology.

PMID:34615922 | DOI:10.1038/s41598-021-99310-z