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23 result(s) for "Akintola, Abimbola A"
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Accuracy of Continuous Glucose Monitoring Measurements in Normo-Glycemic Individuals
The validity of continuous glucose monitoring (CGM) is well established in diabetic patients. CGM is also increasingly used for research purposes in normo-glycemic individuals, but the CGM validity in such individuals is unknown. We studied the accuracy of CGM measurements in normo-glycemic individuals by comparing CGM-derived versus venous blood-derived glucose levels and measures of glycemia and glycemic variability. In 34 healthy participants (mean age 65.7 years), glucose was simultaneously measured every 10 minutes, via both an Enlite® CGM sensor, and in venous blood sampled over a 24-hour period. Validity of CGM-derived individual glucose measurements, calculated measures of glycemia over daytime (09:00h-23:00h) and nighttime (23:00h-09:00h), and calculated measures of glycemic variability (e.g. 24h standard deviation [SD]) were assessed by Pearson correlation coefficients, mean absolute relative difference (MARD) and paired t-tests. The median correlation coefficient between CGM and venous glucose measurements per participant was 0.68 (interquartile range: 0.40-0.78), and the MARD was 17.6% (SD = 17%). Compared with venous sampling, the calculated measure of glycemia during daytime was 0.22 mmol/L higher when derived from CGM, but no difference was observed during nighttime. Most measures of glycemic variability were lower with CGM than with venous blood sampling (e.g., 24h SD: 1.07 with CGM and 1.26 with venous blood; p-value = 0.004). In normo-glycemic individuals, CGM-derived glucose measurements had good agreement with venous glucose levels. However, the measure of glycemia was higher during the day and most measures of glycemic variability were lower when derived from CGM.
Non-pharmacological interventions for improving quality of life of long-term care residents with dementia: a scoping review protocol
IntroductionEvidence concerning the effectiveness of non-pharmacological interventions that are applied to people with dementia living in long-term care facilities is inconsistent. The purpose of this protocol is to describe the methodological considerations that will guide the completion of a scoping review that will inventorise and assess the effectiveness of the various non-pharmacological interventions that are documented in literature for improving quality of life of people with dementia living in long-term care.Methods and analysisThis scoping review will combine the methodology outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews and Guidance for conducting systematic scoping reviews by Peters et al. PubMed; MEDLINE; CINAHL; Embase; Cochrane Database of Systematic Reviews; Cochrane Central Register of Controlled Trials; Emcare; Sociological Abstracts and PsycINFO databases will be searched. Grey literature databases will also be explored. A two-stage screening process consisting of a title and abstract scan and a full-text review will be used to determine the eligibility of studies. Studies, irrespective of design, will be included that quantitatively assess quality of life of long-term care residents who receive non-pharmacological interventions for dementia. A pair of reviewers will independently assess all articles for eligibility, and all eligible articles will be abstracted and charted using a standardised form. The extracted data will undergo a ‘narrative review’ or a descriptive analysis of the contextual or process-oriented data and quantitative analysis reflecting the objectives of this scoping review.Ethics and disseminationResearch ethics approval is not required for this scoping review. This review started off in October 2018, anticipated end date is June 2020. We plan to disseminate this research through publications, presentations at relevant national and international conferences and meetings with relevant stakeholders. This scoping review protocol has been registered at Open Science Framework (https://osf.io/tupbv).
Subclinical hypothyroidism and cognitive function in people over 60 years: a systematic review and meta-analysis
Subclinical hypothyroidism (SCH), defined as elevated thyroid stimulating hormone (TSH) and normal thyroid hormone levels, and cognitive impairment are both common in older people. While the relation between overt hypothyroidism and cognitive impairment is well established, data on the association between SCH and cognitive impairment are conflicting. This systematic review and meta-analysis was performed to assess available evidence on the association of SCH with cognition in community dwelling, relatively healthy older adults. PubMed, EMBASE, Web of Science, COCHRANE, CINAHL, PsycINFO, and Academic Search Premier (January 1966 to April 1, 2015) were searched without language restrictions, as were references of key articles, for studies on the association between SCH and cognition in older adults (>60 years). These studies were reviewed by two independent reviewers according to predefined criteria for eligibility and methodological quality, and data were extracted using standardized forms. Of the 844 reports initially identified, 270 remained after exclusion of duplicates. Of the 270, 15 studies comprising 19,944 subjects, of whom 1,199 had subclinical hypothyroidism were included. Data from the 15 studies was pooled, and meta-analyzed cross-sectionally for global cognition [assessed by Mini-Mental State Examination (MMSE)], executive function, and memory, using random effects models. Pooled effect size (ES) for MMSE was -0.01 (95% CI -0.09, 0.08), with heterogeneity (I (2)) of 55.1%. Pooled ES was < 0.001 (95% CI -0.10, 0.09) for executive function (I (2) = 13.5%), and 0.01 (95% CI -0.12, 0.14) for memory (I (2) = 46.9%). In addition, prospective analysis including four studies showed pooled ES of 0.033 (95% CI -0.001 - 0.067) for MMSE (I (2) < 0.001%), indicating that subclinical hypothyroidism was not significantly associated with accelerated cognitive decline. This systematic review and meta-analysis provides no evidence that supports an association between SCH and cognitive impairment in relatively healthy older adults.
Association between the rs7903146 Polymorphism in the TCF7L2 Gene and Parameters Derived with Continuous Glucose Monitoring in Individuals without Diabetes
The rs7903146-T allele in the transcription factor 7-like 2 (TCF7L2) gene has been associated with impaired pancreatic insulin secretion, enhanced liver glucose production, and an increased risk of type 2 diabetes. Nevertheless, the impact of rs7903146 on daily glucose trajectories remains unclear. Continuous glucose monitoring (CGM) can estimate glycemia and glycemic variability based on consecutive glucose measurements collected over several days. The purpose of the present study was to investigate the associations of rs7903146 with glycemia and glycemic variability in middle-aged participants without diabetes. Complete data from 235 participants without diabetes from the Leiden Longevity Study were available. Participants were divided into two groups based on rs7903146 genotype; rs7903146-CC genotype carriers (N = 123) and rs7903146-CT/TT genotype carriers (N = 112). Validated parameters of glycemia (e.g., mean 24h glucose level) and glycemic variability (e.g., 24h standard deviation) were derived from data collected with a CGM system for a 72-hour period. The study population was on average 64.7 years old (standard deviation = 5.9) and composed of 49.8% of women. Compared with rs7903146-CC carriers, rs7903146-CT/TT carriers exhibited a trend towards a higher mean 24-hour glucose level (5.21 versus 5.32 mmol/L; p-value = 0.15) and a significantly higher mean nocturnal glucose (3:00am- 6:00am; 4.48 versus 4.67 mmol/L; p-value = 0.03) that was explained for 34.6% by body weight and percentage body fat. No differences in measures of glycemic variability between the genotype groups were observed. Despite limited sample size, our study indicates that the rs7903146-T allele in TCF7L2 was associated with a higher mean nocturnal glucose dependent on body composition, which might suggest that rs7902146 affects liver-specific aspects of glucose metabolism.
Characterization of the Hypothalamic-Pituitary-Adrenal-Axis in Familial Longevity under Resting Conditions
The hypothalamic-pituitary-adrenal (HPA)-axis is the most important neuro-endocrine stress response system of our body which is of critical importance for survival. Disturbances in HPA-axis activity have been associated with adverse metabolic and cognitive changes. Humans enriched for longevity have less metabolic and cognitive disturbances and therefore diminished activity of the HPA axis may be a potential candidate mechanism underlying healthy familial longevity. Here, we compared 24-h plasma ACTH and serum cortisol concentration profiles and different aspects of the regulation of the HPA-axis in offspring from long-lived siblings, who are enriched for familial longevity and age-matched controls. Case-control study within the Leiden Longevity study cohort consisting of 20 middle-aged offspring of nonagenarian siblings (offspring) together with 18 partners (controls). During 24 h, venous blood was sampled every 10 minutes for determination of circulatory ACTH and cortisol concentrations. Deconvolution analysis, cross approximate entropy analysis and ACTH-cortisol-dose response modeling were used to assess, respectively, ACTH and cortisol secretion parameters, feedforward and feedback synchrony and adrenal gland ACTH responsivity. Mean (95% Confidence Interval) basal ACTH secretion was higher in male offspring compared to male controls (645 (324-1286) ngl/L/24 h versus 240 (120-477) ng/L/24 h, P = 0.05). Other ACTH and cortisol secretion parameters did not differ between offspring and controls. In addition, no significant differences in feedforward and feedback synchrony and adrenal gland ACTH responsivity were observed between groups. These results suggest that familial longevity is not associated with major differences in HPA-axis activity under resting conditions, although modest, sex-specific differences may exist between groups that might be clinically relevant.
Familial Longevity Is Marked by Lower Diurnal Salivary Cortisol Levels: The Leiden Longevity Study
Reported findings are inconsistent whether hypothalamic-pituitary-adrenal (HPA) signaling becomes hyperactive with increasing age, resulting in increasing levels of cortisol. Our previous research strongly suggests that offspring from long-lived families are biologically younger. In this study we assessed whether these offspring have a lower HPA axis activity, as measured by lower levels of cortisol and higher cortisol feedback sensitivity. Salivary cortisol levels were measured at four time points within the first hour upon awakening and at two time points in the evening in a cohort comprising 149 offspring and 154 partners from the Leiden Longevity Study. A dexamethasone suppression test was performed as a measure of cortisol feedback sensitivity. Age, gender and body mass index, smoking and disease history (type 2 diabetes and hypertension) were considered as possible confounding factors. Salivary cortisol secretion was lower in offspring compared to partners in the morning (Area Under the Curve = 15.6 versus 17.1 nmol/L, respectively; p = 0.048) and in the evening (Area Under the Curve = 3.32 versus 3.82 nmol/L, respectively; p = 0.024). Salivary cortisol levels were not different after dexamethasone (0.5 mg) suppression between offspring and partners (4.82 versus 5.26 nmol/L, respectively; p = 0.28). Offspring of nonagenarian siblings are marked by a lower HPA axis activity (reflected by lower diurnal salivary cortisol levels), but not by a difference in cortisol feedback sensitivity. Further in-depth studies aimed at characterizing the HPA axis in offspring and partners are needed.
Growth hormone secretion is diminished and tightly controlled in humans enriched for familial longevity
Summary Reduced growth hormone (GH) signaling has been consistently associated with increased health and lifespan in various mouse models. Here, we assessed GH secretion and its control in relation with human familial longevity. We frequently sampled blood over 24 h in 19 middle-aged offspring of long-living families from the Leiden Longevity Study together with 18 of their partners as controls. Circulating GH concentrations were measured every 10 min and insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein 3 (IGFBP3) every 4 h. Using deconvolution analysis, we found that 24-h total GH secretion was 28% lower (P = 0.04) in offspring [172 (128-216) mU L-1] compared with controls [238 (193-284) mU L-1]. We used approximate entropy (ApEn) to quantify the strength of feedback/feedforward control of GH secretion. ApEn was lower (P = 0.001) in offspring [0.45 (0.39-0.53)] compared with controls [0.66 (0.56-0.77)], indicating tighter control of GH secretion. No significant differences were observed in circulating levels of IGF-1 and IGFBP3 between offspring and controls. In conclusion, GH secretion in human familial longevity is characterized by diminished secretion rate and more tight control. These data imply that the highly conserved GH signaling pathway, which has been linked to longevity in animal models, is also associated with human longevity.
Associations between insulin action and integrity of brain microstructure differ with familial longevity and with age
Impaired glucose metabolism and type 2 diabetes have been associated with cognitive decline, dementia, and with structural and functional brain features. However, it is unclear whether these associations differ in individuals that differ in familial longevity or age. Here, we investigated the association between parameters of glucose metabolism and microstructural brain integrity in offspring of long-lived families (\"offspring\") and controls; and age categories thereof. From the Leiden Longevity Study (LLS), 132 participants underwent an oral glucose tolerance test (OGTT) to assess glycemia [fasted glucose and glucose area-under-the-curve (AUC)], insulin resistance [fasted insulin, AUCinsulin, and homeostatic model assessment of insulin resistance (HOMA-IR)], and pancreatic Beta cell secretory capacity (insulinogenic index). 3 Tesla MRI and Magnetization Transfer (MT) imaging MT-ratio (MTR) peak-height was used to quantify differences in microstructural brain parenchymal tissue homogeneity that remain invisible on conventional MRI. Analyses were performed in offspring and age-matched controls, with and without stratification for age. In the full offspring group only, reduced MTR peak-height in gray and white matter was inversely associated with AUCinsulin, fasted insulin, HOMA-IR and insulinogenic-index (all p < 0.01). When dichotomized for age (≤65 years and >65 years): in younger controls, significantly stronger inverse associations were observed between MTR peak-height and fasted glucose, AUCglucose, fasted insulin, AUCinsulin and HOMA-IR in gray matter; and for AUCglucose, fasted insulin and HOMA-IR in white matter (all P-interaction < 0.05). Although the strength of the associations tended to attenuate with age in the offspring group, the difference between age groups was not statistically significant. Thus, associations between impaired insulin action and reduced microstructural brain parenchymal tissue homogeneity were stronger in offspring compared to controls, and seemed to diminish with age.
Interrelationships Between Pituitary Hormones as Assessed From 24-hour Serum Concentrations in Healthy Older Subjects
Abstract Context Hormones of the hypothalamic-pituitary-target gland axes are mostly investigated separately, whereas the interplay between hormones might be as important as each separate hormonal axis. Objective Our aim is to determine the interrelationships between GH, TSH, ACTH, and cortisol in healthy older individuals. Design We made use of 24-hour hormone serum concentrations assessed with intervals of 10 minutes from 38 healthy older individuals with a mean age (SD) of 65.1 (5.1) years from the Leiden Longevity Study. Cross-correlation analyses were performed to assess the relative strength between 2 24-hour hormone serum concentration series for all possible time shifts. Cross-approximate entropy was used to assess pattern synchronicity between 2 24-hour hormone serum concentration series. Results Within an interlinked hormonal axis, ACTH and cortisol were positively correlated with a mean (95% confidence interval) correlation coefficient of 0.78 (0.74–0.81) with cortisol following ACTH concentrations with a delay of 10 minutes. Between different hormonal axes, we observed a negative correlation coefficient between cortisol and TSH of -0.30 (-0.36 to -0.25) with TSH following cortisol concentrations with a delay of 170 minutes. Furthermore, a positive mean (95% confidence interval) correlation coefficient of 0.29 (0.22–0.37) was found between TSH and GH concentrations without any delay. Moreover, cross-approximate entropy analyses showed that GH and cortisol exhibit synchronous serum concentration patterns. Conclusions This study demonstrates that interrelations between hormones from interlinked as well as different hypothalamic-pituitary-target gland axes are observed in healthy older individuals. More research is needed to determine the biological meaning and clinical consequences of these observations.
Validation of urinary biomarkers for accurate diagnosis of urinary tract infections in older adults across primary care, hospitals and long-term care facilities in the Netherlands and UK (UTI-GOLD): a multicentre observational study protocol
IntroductionUrinary tract infections (UTIs) are highly prevalent and pose a significant burden among older adults. Accurate diagnosis in this population is challenging due to the high prevalence of pre-existing lower urinary tract symptoms, inability to express symptoms and asymptomatic bacteriuria. Current diagnostic tests are unreliable, often resulting in over- and underdiagnosis. A previous pilot study proposed a higher cut-off for pyuria and identified five promising biomarkers for the diagnosis of UTIs in older adults. The UTI-GOLD study aims to validate these five new biomarkers and the higher leucocyte cut-off as a diagnostic tool for UTIs in older people in a real-world setting.Methods and analysisBetween August 2024 and December 2027, an observational multicentre diagnostic accuracy study is being conducted across primary, secondary and tertiary healthcare facilities in the Netherlands and the UK. Adults ≥65 years with a suspected UTI will be considered eligible. Patients with pre-existing decision-making incapacity or an indwelling catheter will be excluded. UTI will be defined according to an international consensus-based reference standard. Biomarkers will be measured by liquid chromatography-mass spectrometry (neutrophil gelatinase-associated lipocalin, tissue inhibitor of metalloproteinase 2 and CXC motif chemokine ligand 9) and enzyme-linked immunosorbent assay (interleukin 6 and azurocidin). Pyuria will be quantified by automated microscopy and/or flow cytometry. Diagnostic accuracy measures will be calculated using the receiver operating characteristic curves, and sensitivity, specificity, likelihood ratios and predictive values will be reported for optimal cut-offs.Ethics and disseminationThe protocol was reviewed by the local Leiden University Medical Center research committee, who declared on 15 April 2024 that the medical research involving human subject act (Dutch abbreviation: WMO) does not apply to the current study (reference number nWMODIV2_2024025). The study also received approval from the NHS Research Ethics Committee in the UK (reference number 24/LO/0649).The study findings will be published in a peer-reviewed journal, presented at academic congresses and shared with healthcare providers.Trial registration numberThe study was registered at clinicaltrial.gov on the 24 September 2024 with registration number: NCT06610721.