scholarly journals Effects of Age and Serum 25-OH-Vitamin D on Serum Parathyroid Hormone Levels

2012 ◽  
Vol 97 (11) ◽  
pp. 3989-3995 ◽  
Author(s):  
A. Valcour ◽  
F. Blocki ◽  
D. M. Hawkins ◽  
Sudhaker D. Rao
Keyword(s):  
Vitamin D ◽  
Calcium Absorption ◽  
Small Sample Size ◽  
International Workshop ◽  
Large Population ◽  
Small Sample ◽  
Reference Laboratory ◽  
Population Database ◽  
Age Related ◽  
Serum Pth

Context: Several studies define optimal serum 25-hydroxyvitamin D (25-OHD) levels based on serum PTH level reaching an asymptote. However, results differ widely, ranging from 25-OHD levels of 12–44 ng/ml: many studies are constrained by small sample size. Objective: The objective of the study was to determine the relationship between serum PTH and 25-OHD levels and age in a very large reference laboratory database. Design: This was a detailed cross-sectional analysis of 312,962 paired serum PTH and 25-OHD levels measured from July 2010 to June 2011. Results: Median PTH levels and the proportion of patients (PTH > 65 pg/ml), from 63 successive 25-OHD frequency classes of 5000 patients, provide smooth, exceptionally well-fitted curves (R2 = 0.994 and R2 = 0.995, respectively) without discernible inflection points or asymptotes but with striking age dependencies. Serum 25-OHD was below the recent Institute of Medicine sufficiency guidance of 20 ng/ml in 27% (85,000) of the subjects. More importantly, 40 and 51% of subjects (serum 25-OHD <20 and 10 ng/ml, respectively) had biochemical hyperparathyroidism (PTH > 65 pg/ml). Conclusions: This analysis, despite inevitable inherent limitations, introduces several clinical implications. First, median 25-OHD-dependent PTH levels revealed no threshold above which increasing 25-OHD fails to further suppress PTH. Second, the large number of subjects with 25-OHD deficiency and hyperparathyroidism reinforces the Third International Workshop on Asymptomatic Primary Hyper parathyroidism's recommendations to test for, and replete, vitamin D depletion before considering parathyroidectomy. Third, strong age dependency of the PTH-25-OHD relationship likely reflects the composite effects of age-related decline in calcium absorption and renal function. Finally, this unselected large population database study could guide clinical management of patients based on an age-dependent, PTH-25-OHD continuum.

scholarly journals Blinding in electric current stimulation in subacute neglect patients with current densities of 0.8 A/m2: a cross-over pilot study

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Anna Gorsler ◽  
Ulrike Grittner ◽  
Nadine Külzow ◽  
Torsten Rackoll
Keyword(s):  
Pilot Study ◽  
Electric Fields ◽  
Standard Care ◽  
Small Sample Size ◽  
Small Sample ◽  
Related Factors ◽  
Attentional Deficits ◽  
Age Related ◽  
Current Densities ◽  
Improve Standard

Abstract Objective Neglect after stroke is a disabling disorder and its rehabilitation is a major challenge. Transcranial direct current stimulation (tDCS) seems to be a promising adjuvant technique to improve standard care neglect therapy. Since electric fields are influenced by age-related factors, higher current densities are probably needed for effective treatment in aged stroke patients. Validation of treatment efficacy requires sham-controlled experiments, but increased current densities might comprise blinding. Therefore, a pilot study was conducted to test sham adequacy when using current density of 0.8 A/m2. Whether especially neglect patients who mainly suffer from perceptual and attentional deficits are able to differentiate beyond chance active from sham tDCS was investigated in a randomized cross-over design (active/sham stimulation) in 12 early subacute patients with left-sided hemineglect. Stimulation (0.8 A/m2) was performed simultaneous to standard care neglect therapy. Results Odds ratio of correct guessing an atDCS condition compared to wrongly judge an atDCS condition as sham was 10.00 (95%CI 0.65–154.40, p = 0.099). However, given the small sample size and high OR, although likely somewhat overestimated, results require careful interpretation and blinding success in neglect studies with current densities of 0.8 A/m2 should be further confirmed.

scholarly journals Assessing Biomarkers of Breast Cancer Risk in Underserved Women in a Midwestern County

2021 ◽  
Vol 12 ◽  
pp. 215013272110177
Author(s):  
Marla A. DeWitt ◽  
Ivana T. Croghan ◽  
Celine M. Vachon ◽  
Thomas D. Thacher ◽  
Marcia R. Venegas Pont ◽  
...  
Keyword(s):  
Vitamin D ◽  
Mammographic Density ◽  
Small Sample Size ◽  
Vitamin D Insufficiency ◽  
Screening Mammography ◽  
Small Sample ◽  
Vitamin D Status ◽  
Small Pilot Study ◽  
Unexpected Findings

Objective: The primary aim of this study was to evaluate the feasibility of collecting risk factor information and accessing digitized mammographic data in a medically marginalized population. A secondary aim was to examine the association between vitamin D status and mammographic density. Methods: Breast-screening examinations were provided for age-appropriate patients, and a referral for no-cost screening mammography was offered. Study participants were asked to undergo 25-hydroxyvitamin D testing at mammography and 1-year follow-up. Results: Of 62 women approached, 35 (56%) consented to participate. Of 32 participants who had baseline mammography, the median mammographic density measured by VolparaDensity (Volpara Solutions Limited) was 5.7%. After 1 year, 9 women obtained follow-up mammograms, with a median density of 5.7%. Vitamin D status was measured for 31 participants at baseline and 13 participants in the following year. Insufficient vitamin D status (<30 ng/mL) was noted in 77% at each time point. Mammographic density was not significantly correlated with vitamin D status ( P = .06). Conclusions: On the basis of this small pilot study, vitamin D insufficiency is common in this study population. Owing to the small sample size, an association between vitamin D insufficiency and breast density was not clear. Additional unexpected findings included substantial barriers in initial access to care and longitudinal follow-up in this population. Further study of these issues is needed.

scholarly journals COVID-19 in age-related neurodegenerative diseases: is there a role for vitamin D3 as a possible therapeutic strategy?

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Milena de Barros Viana ◽  
Bárbara dos Anjos Rosário ◽  
Maria de Fátima Santana de Nazaré ◽  
Débora Estadella ◽  
Daniel Araki Ribeiro ◽  
...  
Keyword(s):  
Vitamin D ◽  
Therapeutic Strategy ◽  
Clinical Symptoms ◽  
Large Population ◽  
Mortality Rates ◽  
Vitamin D Supplementation ◽  
World Health ◽  
Age Related ◽  
Alzheimer’S Diseases ◽  
Alzheimer's Diseases

AbstractThe coronavirus disease (COVID-19), identified in Wuhan, China, on December 2019, was declared a pandemic by the World Health Organization, on March, 2020. Since then, efforts have been gathered to describe its clinical course and to determine preventive measures and treatment strategies. Adults older than 65 years of age are more susceptible to serious clinical symptoms and present higher mortality rates. Angiotensin-converting enzyme 2 (ACE2) is a major receptor for some coronavirus infection, including SARS-COV-2, but is also a crucial determinant in anti-inflammation processes during the renin–angiotensin system (RAS) functioning – converting angiotensin II to angiotensin 1–7. The decline in ACE2 expression that occurs with aging has been associated to the higher morbidity and mortality rates in older adults. These observations highlight the importance of investigating the association between COVID-19 and age-related neurodegenerative disorders, i.e., Parkinson’s and Alzheimer’s diseases. A possible option to reduce the risk of COVID-19 is vitamin D supplementation, due to its anti-inflammatory and immune-system-modulating effects. It has also been suggested that vitamin D supplementation plays a role in slowing progression of Parkinson and Alzheimer. The present study is a literature review of articles published on the theme COVID-19, Parkinson and Alzheimer’s diseases, and the role played by vitamin D. PUBMED, MEDLINE, and EMBASE databases were consulted. Results confirm neurodegenerative and neuroinflammatory effects of COVID-19, aggravated in Parkinson’s and Alzheimer’s patients, and the important role of vitamin D as a possible therapeutic strategy. Nevertheless, randomized controlled trials and large population studies are still warranted.

scholarly journals Time-restricted feeding from adulthood to old age improves biconditional associative learning in geriatric rats regardless of macronutrient composition

2020 ◽  
Author(s):  
Abbi R. Hernandez ◽  
Quinten P. Federico ◽  
Sara N. Burke
Keyword(s):  
Dietary Intervention ◽  
Small Sample Size ◽  
Control Diet ◽  
Small Sample ◽  
Restricted Feeding ◽  
Macronutrient Composition ◽  
Mature Adult ◽  
Age Related ◽  
Feeding Regimen ◽  
Ad Libitum

AbstractDeclining health and cognition are hallmarks of advanced age that reduce both the quality and length of the lifespan. While caloric restriction has been highlighted as a dietary intervention capable of improving the healthspan by restoring metabolic function in late life, time-restricted feeding and changes in dietary macronutrient composition may be more feasible alternatives with similar health outcomes. To investigate the potential of these two interventions, a pilot cohort of fully mature adult rats were placed on a time-restricted feeding regimen of a ketogenic or micronutrient and calorically matched control diet from 8 to 21 months of age. A third group of rats was permitted to eat standard chow ad libitum. At 22 months, all rats were then placed on time-restricted feeding and tested on a biconditional association task. While the data presented here are preliminary (small sample size of 3-4/diet group), additional animals are currently undergoing the feeding regimen, and will be added into the behavioral studies at a later date. For the current data, regardless of dietary composition, time-restricted-fed rats performed significantly better than ad libitum-fed rats. This observation could not be accounted for by differences in motivation, procedural or sensorimotor impairments, indicating that mid-life dietary interventions capable of preventing metabolic impairments may also serve to prevent age-related cognitive decline.

scholarly journals Genotyping an <i>Emiliania huxleyi</i> (Prymnesiophyceae) bloom event in the North Sea reveals evidence of asexual reproduction

2014 ◽  
Vol 11 (3) ◽  
pp. 4359-4408 ◽  
Author(s):  
S. A. Krueger-Hadfield ◽  
C. Balestreri ◽  
J. Schroeder ◽  
A. Highfield ◽  
P. Helaouët ◽  
...  
Keyword(s):  
North Sea ◽  
Asexual Reproduction ◽  
Small Sample Size ◽  
Large Population ◽  
Emiliania Huxleyi ◽  
Small Sample ◽  
Phytoplankton Species ◽  
The North ◽  
Generation Times ◽  
The North Sea

Abstract. Due to the unprecedented rate at which our climate is changing, the ultimate consequence for many species is likely to be either extinction or migration to an alternate habitat. Certain species might, however, evolve at a rate that could make them resilient to the effects of a rapidly changing environment. This scenario is most likely to apply to species that have large population sizes and rapid generation times, such that the genetic variation required for adaptive evolution can be readily supplied. Emiliania huxleyi (Lohm.) Hay and Mohler (Prymnesiophyceae) is likely to be such a species as it is the most conspicuous extant calcareous phytoplankton species in our oceans with generation times of 1 day−1. Here we report on a validated set of microsatellites, in conjunction with the coccolithophore morphology motif genetic marker, to genotype 93 clonal isolates collected from across the world. Of these, 52 came from a single bloom event in the North Sea collected on the D366 UK Ocean Acidification cruise in June-July 2011. There were 26 multilocus genotypes (MLGs) encountered only once in the North Sea bloom and 8 MLGs encountered twice or up to six times. Each of these repeated MLGs exhibited Psex values of less than 0.05 indicating each repeated MLG was the product of asexual reproduction and not separate meiotic events. In addition, we show that the two most polymorphic microsatellite loci, EHMS37 and P01E05, are reporting on regions likely undergoing rapid genetic drift during asexual reproduction. Despite the small sample size, there were many more repeated genotypes than previously reported for other bloom-forming phytoplankton species, including a previously genotyped E. huxleyi bloom event. This study challenges our current assumption that sex is the predominant mode of reproduction during bloom events. Whilst genetic diversity is high amongst extant populations of E. huxleyi, the root cause for this diversity and ultimate fate of these populations still requires further examination. Nonetheless, we show that certain CMM genotypes are found everywhere; while others appear to have a regional bias.

Optical coherence tomography angiography in amblyopia: A critical update on current understandings and future perspectives

2021 ◽  
pp. 112067212110425
Author(s):  
Amar Pujari ◽  
Gunjan Saluja ◽  
Rohan Chawla ◽  
Asha Samdani ◽  
Swati Phuljhele ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Small Sample Size ◽  
Small Sample ◽  
Age Related Macular Degeneration ◽  
Optical Coherence ◽  
Patient Profile ◽  
Age Related ◽  
Choroidal Vasculature

Optical coherence tomography angiography (OCTA) is a non-invasive tool to assess the retino-choroidal vasculature in vivo. It tracks the red blood cell movement and maps the vasculature in quick succession. In routine, diabetic retinopathy, age related macular degeneration, central serous chorioretinopathy, and others are commonly being studied to unveil its clinic role. On the other hand, amblyopia is a condition where the visual acuity is subnormal due to non-organic causes in the eye. But the OCTA studies till now have shown variable changes along retino-choroidal vasculature. Hence, to comprehend the existing literature knowledge, a systematic literature search was carried out and the original works describing novel findings in amblyopic eyes on OCTA were included. Upon detailed assessment, firstly, the disturbed vasculature along superficial retinal plexus, deeper retinal plexus, and choroidal plexus were evident in most untreated amblyopic eyes. However, such changes were not uniform, which is due to noted heterogenic patient profile, small sample size, biometric biases, non-uniform algorithms, and other factors. And to note, even in presence of such diverse changes, almost all the authors stated a plausible explanation for their notable changes. Secondly, the utility of OCTA in identifying vascular changes with standard treatments and segregation of visual beneficiaries from non-beneficiaries were possible. Hence, to conclude, OCTA is a valuable tool which can provide valuable useful insights into the amblyopic eyes during pre and post treatment periods. However, to gather more concrete evidence for clinical benefits, systematic, homogenous, and better structured clinical studies are mandated.

Effect of supplementing high levels of vitamin D3 on calcium homeostasis of steers fed barley-based finishing diets

2004 ◽  
Vol 84 (1) ◽  
pp. 81-89
Author(s):  
G. Aranda-Osorio ◽  
A. A. Olkowski ◽  
T. A. McAllister ◽  
A. Van Kessel ◽  
J. J. McKinnon
Keyword(s):  
Vitamin D ◽  
Calcium Homeostasis ◽  
Repeated Measures ◽  
Calcium Absorption ◽  
Barley Grain ◽  
Plasma Vitamin ◽  
Beef Tenderness ◽  
Finishing Diets ◽  
Serum Pth ◽  
Barley Silage

The objective of this study was to evaluate the effect of supplementing high levels of vitamin D3 to steers fed barley-grain-based finishing diets on Ca metabolism. Fifteen Hereford steers (607 ± 12 kg) were individually penned and fed at 0800 and 1600 with a ration consisting of 90% barley-grain-based concentrate and 10% barley silage [dry matter (DM) basis]. Steers were randomly assigned to one of three treatments: 0, 2.5 or 5 million IU (MIU) of vitamin D3 steer-1 d-1 for 7 d. Daily blood samples were obtained for measurement of serum for total and ionized Ca, parathyroid hormone (PTH) and calcitonin and plasma for vitamin D3 and 25(OH)D3. Data were analyzed by repeated measures analysis and single degree of freedom contrasts. Feed intake was depressed relative to control animals by 18 and 37% for the 2.5 and 5 MIU D3 treatments, respectively. Relative to controls, total and ionized Ca increased (P < 0.05) by 8 and 19% and 6 and 18% for the 2.5 and 5 MIU D3 treatments, respectively. Serum PTH concentrations were reduced (P < 0.05) by vitamin D3 feeding with the greatest reduction seen with animals fed the 5 MIU treatment. Calcitonin values were not (P > 0.05) affected. Relative to controls, plasma vitamin D3 concentrations increased (P < 0.05) in a quadratic fashion over time with vitamin D3 supplementation, while that of 25(OH)D3 increased (P < 0.05) in a linear fashion. It was concluded that the increase in serum calcium was stimulated by a rise in plasma vitamin D3 and the resulting increased 25(OH)D3 concentrations, which have been shown to influence calcium absorption either directly or via induced synthesis of 1,25(OH)2D3. Key words: Calcium homeostasis, vitamin D3, cattle, beef tenderness

Twin studies and the heritability of MS: a conclusion

2009 ◽  
Vol 15 (6) ◽  
pp. 661-667 ◽  
Author(s):  
CH Hawkes ◽  
AJ Macgregor
Keyword(s):  
Small Sample Size ◽  
Large Population ◽  
Twin Studies ◽  
Genetic Effect ◽  
Population Based ◽  
Small Sample ◽  
Genetic Contribution ◽  
Research Strategies ◽  
Control Approach ◽  
Genes And Environment

Objective The classical twin study has the potential to evaluate the relative contribution of genes and environment and guide further research strategies, provided the sampling and methods of analysis are correct. We wish to review all the more informative twin studies on multiple sclerosis (MS). Methods We examined six large population-based twin studies in MS and calculated indices of heritability (h2), which is the traditional method of assessing genetic contribution to disease and to allow comparison between studies. Results This index was found to vary widely from 0.25 to 0.76 with large confidence intervals that reflect small sample size and prevent robust interpretation. Conclusion Overall the studies support a genetic contribution to disease; however, the imprecision of the heritability estimates and potential biases that they contain mean that very little inference can be drawn its exact size. Given that the magnitude of genetic effect cannot be measured because of the relative infrequency of MS; the consequent difficulty in collecting an informative sample; and in many countries, the lack of a comprehensive twin register, we suggest that further twin prevalence surveys should not be undertaken. Twin studies could be used more effectively in other ways, such as the co-twin case–control approach.

Hematologic, Biochemical, and Endocrine Parameters in Horses With Tooth Resorption and Hypercementosis

2017 ◽  
Vol 34 (3) ◽  
pp. 155-160 ◽  
Author(s):  
Edward T. Earley ◽  
Jennifer R. Rawlinson ◽  
Robert M. Baratt ◽  
Stephen S. Galloway ◽  
Rebecca C. Smedley ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Complete Blood Count ◽  
Small Sample Size ◽  
Large Population ◽  
The United States ◽  
Small Sample ◽  
Radiographic Examination ◽  
Pars Intermedia ◽  
Tooth Resorption ◽  
Endocrine Parameters

Background: Equine odontoclastic tooth resorption and hypercementosis (EOTRH) is a frequently diagnosed condition in adult horses. The underlying etiology is still unknown. Hematologic, biochemical, and endocrine values have not been reported in EOTRH-affected horses. Objectives: The main objective of the study was to describe the hematologic, biochemical, and endocrine parameters in horses with EOTRH. Study Design: Descriptive cross-sectional study of client-owned animals with EOTRH. Methods: A complete blood count, biochemistry panel, and endocrine profile were performed in horses diagnosed with EOTRH. Diagnosis was based on oral and radiographic examination findings and confirmed with histopathology. Results: Eighteen horses with EOTRH aged 10 to 32 years from various regions of the United States were sampled. The only consistent abnormality on the complete blood cell count and chemistry panel was hypoalbuminemia (88%). Endocrine parameters demonstrated no major abnormalities in the functioning of the thyroid and pituitary pars intermedia. The parathyroid hormone concentration was increased in 7 (47%) of 15 horses with an elevated 25-hydroxy vitamin D in 3 (17%) of 17 horses. Main Limitations: The main limitations of this study are the small sample size and lack of age-matched and management-matched control horses. Conclusions: The relevance of elevated parathyroid hormone in this study cannot be determined due to the lack of age-based controls and large population studies. With the small population evaluated in this study, there are no obvious hematological, biochemical, and endocrine changes evident. Further evaluation with signalment-matched controls will be necessary to evaluate some trends noted in the laboratory values.

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