Incidence of and risk factors of chronic kidney disease: Results of a nationwide study in Iceland

Background - Information on the incidence of chronic kidney disease (CKD) in the general population is scarce. This study examined the incidence and risk factors of CKD stages 1–5 in Iceland, based on multiple markers of kidney damage. Methods - All serum creatinine (SCr) values, urine protein measurements and diagnosis codes for kidney diseases and comorbid conditions for people aged ≥18 years were obtained from electronic medical records of all healthcare institutions in Iceland in 2008–2016. CKD was defined according to the Kidney Disease: Improving Global Outcomes (KDIGO) criteria as evidence for kidney damage and/or estimated glomerular filtration rate (eGFR) 3 months. Alternatively, CKD was defined using age-adapted eGFR thresholds. Mean annual age-standardized incidence of CKD was calculated for persons without CKD at study entry. Risk factor assessment was based on International Classification of Diseases diagnosis codes. Incidence was reported per 100 000 population. Results - We retrieved 1 820 990 SCr values for 206 727 persons. Median age was 45 years (range, 18–106) and 47% were men. Mean annual age-standardized incidence of CKD per 100 000 was 649 in men and 694 in women, and 480 in men and 522 in women using age-adapted eGFR thresholds. The incidence reached over 3000 in men and women aged >75 years. Traditional CKD risk factors, such as acute kidney injury, diabetes, hypertension and cardiovascular disease, as well as less well characterized risk factors, including chronic lung disease, malignancy and major psychiatric illness were associated with increased risk of CKD, and the same was true for obesity and sleep apnoea in women. Conclusion - The annual incidence of CKD, with strict adherence to the KDIGO criteria, was <0.7% but markedly lower using age-adapted eGFR thresholds. Apart from acute kidney injury, the observed risk factors comprised chronic and potentially modifiable disorders

Association of eGFR and mortality with use of a joint model: results of a nationwide study in Iceland

Objectives. Prior studies on the association of estimated glomerular filtration rate (eGFR) and mortality have failed to include methods to account for repeated eGFR determinations. The aim of this study was to estimate the association between eGFR and mortality in the general population in Iceland employing a joint model. Methods. We obtained all serum creatinine and urine protein measurements from all clinical laboratories in Iceland in the years 2008–16. Clinical data were obtained from nationwide electronic medical records. eGFR was calculated using the Chronic Kidney Disease Epidemiology Collaboration equation and categorized as follows: 0–29, 30–44, 45–59, 60–74, 75– 89, 90–104 and >104 mL/min/1.73 m2. A multiple imputation method was used to account for missing urine protein data. A joint model was used to assess risk of all-cause mortality. Results. We obtained 2 120 147 creatinine values for 218 437 individuals, of whom 84 364 (39%) had proteinuria measurements available. Median age was 46 (range 18–106) years and 47% were men. Proteinuria associated with increased risk of death for all eGFR categories in persons of all ages. In persons ≤65 years, the lowest risk was observed for eGFR of 75–89 mL/min/1.73 m2 without proteinuria. For persons aged >65 years, the lowest risk was observed for eGFR of 60–74 mL/min/1.73 m2 without proteinuria. eGFR of 45–59 mL/min/1.73 m2 without proteinuria did not associate with increased mortality risk in this age group. eGFR >104 mL/min/1.73 m2 associated with increased mortality. Conclusions. These results lend further support to the use of age-adapted eGFR thresholds for defining chronic kidney disease. Very high eGFR needs to be studied in more detail with regard to mortalit

Association of glial and neuronal degeneration markers with Alzheimer's disease cerebrospinal fluid profile and cognitive functions.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked DownloadBackground: Neuroinflammation has gained increasing attention as a potential contributing factor in the onset and progression of Alzheimer's disease (AD). The objective of this study was to examine the association of selected cerebrospinal fluid (CSF) inflammatory and neuronal degeneration markers with signature CSF AD profile and cognitive functions among subjects at the symptomatic pre- and early dementia stages. Methods: In this cross-sectional study, 52 subjects were selected from an Icelandic memory clinic cohort. Subjects were classified as having AD (n = 28, age = 70, 39% female, Mini-Mental State Examination [MMSE] = 27) or non-AD (n = 24, age = 67, 33% female, MMSE = 28) profile based on the ratio between CSF total-tau (T-tau) and amyloid-β1-42 (Aβ42) values (cut-off point chosen as 0.52). Novel CSF biomarkers included neurofilament light (NFL), YKL-40, S100 calcium-binding protein B (S100B) and glial fibrillary acidic protein (GFAP), measured with enzyme-linked immunosorbent assays (ELISAs). Subjects underwent neuropsychological assessment for evaluation of different cognitive domains, including verbal episodic memory, non-verbal episodic memory, language, processing speed, and executive functions. Results: Accuracy coefficient for distinguishing between the two CSF profiles was calculated for each CSF marker and test. Novel CSF markers performed poorly (area under curve [AUC] coefficients ranging from 0.61 to 0.64) compared to tests reflecting verbal episodic memory, which all performed fair (AUC > 70). LASSO regression with a stability approach was applied for the selection of CSF markers and demographic variables predicting performance on each cognitive domain, both among all subjects and only those with a CSF AD profile. Relationships between CSF markers and cognitive domains, where the CSF marker reached stability selection criteria of > 75%, were visualized with scatter plots. Before calculations of corresponding Pearson's correlations coefficients, composite scores for cognitive domains were adjusted for age and education. GFAP correlated with executive functions (r = - 0.37, p = 0.01) overall, while GFAP correlated with processing speed (r = - 0.68, p < 0.001) and NFL with verbal episodic memory (r = - 0.43, p = 0.02) among subjects with a CSF AD profile. Conclusions: The novel CSF markers NFL and GFAP show potential as markers for cognitive decline among individuals with core AD pathology at the symptomatic pre- and early stages of dementia. Keywords: AD biomarker profile; Alzheimer’s disease; Cerebrospinal fluid; Cognitive domains; Glial fibrillary acidic protein; Neurofilament light; S100 calcium-binding protein B; YKL-40.St. Josef's Hospital Fund, Reykjavik, Iceland Landspitali University Hospital Research Fund Icelandic Research Fund of the Icelandic Centre for Researc

Phenotypic Displays of Cholinergic Enzymes Associate With Markers of Inflammation, Neurofibrillary Tangles, and Neurodegeneration in Pre- and Early Symptomatic Dementia Subjects

Funding Information: This study was supported by the St. Josef’s Hospital Fund, Reykjavik, Iceland, the Landspitali University Hospital Research Fund, and the Icelandic Research Fund of the Icelandic Centre for Research (163172-051). Publisher Copyright: Copyright © 2022 Teitsdottir, Darreh-Shori, Lund, Jonsdottir, Snaedal and Petersen.Background: Cholinergic drugs are the most commonly used drugs for the treatment of Alzheimer’s disease (AD). Therefore, a better understanding of the cholinergic system and its relation to both AD-related biomarkers and cognitive functions is of high importance. Objectives: To evaluate the relationships of cerebrospinal fluid (CSF) cholinergic enzymes with markers of amyloidosis, neurodegeneration, neurofibrillary tangles, inflammation and performance on verbal episodic memory in a memory clinic cohort. Methods: In this cross-sectional study, 46 cholinergic drug-free subjects (median age = 71, 54% female, median MMSE = 28) were recruited from an Icelandic memory clinic cohort targeting early stages of cognitive impairment. Enzyme activity of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) was measured in CSF as well as levels of amyloid-β1–42 (Aβ42), phosphorylated tau (P-tau), total-tau (T-tau), neurofilament light (NFL), YKL-40, S100 calcium-binding protein B (S100B), and glial fibrillary acidic protein (GFAP). Verbal episodic memory was assessed with the Rey Auditory Verbal Learning (RAVLT) and Story tests. Results: No significant relationships were found between CSF Aβ42 levels and AChE or BuChE activity (p > 0.05). In contrast, T-tau (r = 0.46, p = 0.001) and P-tau (r = 0.45, p = 0.002) levels correlated significantly with AChE activity. Although neurodegeneration markers T-tau and NFL did correlate with each other (r = 0.59, p < 0.001), NFL did not correlate with AChE (r = 0.25, p = 0.09) or BuChE (r = 0.27, p = 0.06). Inflammation markers S100B and YKL-40 both correlated significantly with AChE (S100B: r = 0.43, p = 0.003; YKL-40: r = 0.32, p = 0.03) and BuChE (S100B: r = 0.47, p < 0.001; YKL-40: r = 0.38, p = 0.009) activity. A weak correlation was detected between AChE activity and the composite score reflecting verbal episodic memory (r = −0.34, p = 0.02). LASSO regression analyses with a stability approach were performed for the selection of a set of measures best predicting cholinergic activity and verbal episodic memory score. S100B was the predictor with the highest model selection frequency for both AChE (68%) and BuChE (73%) activity. Age (91%) was the most reliable predictor for verbal episodic memory, with selection frequency of both cholinergic enzymes below 10%. Conclusions: Results indicate a relationship between higher activity of the ACh-degrading cholinergic enzymes with increased neurodegeneration, neurofibrillary tangles and inflammation in the stages of pre- and early symptomatic dementia, independent of CSF Aβ42 levels.Peer reviewe

Cerebrospinal Fluid C18 Ceramide Associates with Markers of Alzheimer's Disease and Inflammation at the Pre- and Early Stages of Dementia.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked DownloadBackground: Understanding how dysregulation in lipid metabolism relates to the severity of Alzheimer's disease (AD) pathology might be critical in developing effective treatments. Objective: To identify lipid species in cerebrospinal fluid (CSF) associated with signature AD pathology and to explore their relationships with measures reflecting AD-related processes (neurodegeneration, inflammation, deficits in verbal episodic memory) among subjects at the pre- and early symptomatic stages of dementia. Methods: A total of 60 subjects that had been referred to an Icelandic memory clinic cohort were classified as having CSF AD (n = 34) or non-AD (n = 26) pathology profiles. Untargeted CSF lipidomic analysis was performed using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS) for the detection of mass-to-charge ratio (m/z) features. CSF proteins reflecting neurodegeneration (neurofilament light [NFL]) and inflammation (chitinase-3-like protein 1 [YKL-40], S100 calcium-binding protein B [S100B], glial fibrillary acidic protein [GFAP]) were also measured. Rey Auditory Verbal Learning (RAVLT) and Story tests were used for the assessment of verbal episodic memory. Results: Eight out of 1008 features were identified as best distinguishing between the CSF profile groups. Of those, only the annotation of the m/z feature assigned to lipid species C18 ceramide was confirmed with a high confidence. Multiple regression analyses, adjusted for age, gender, and education, demonstrated significant associations of CSF core AD markers (Aβ42: st.β= -0.36, p = 0.007; T-tau: st.β= 0.41, p = 0.005) and inflammatory marker S100B (st.β= 0.51, p = 0.001) with C18 ceramide levels. Conclusion: Higher levels of C18 ceramide associated with increased AD pathology and inflammation, suggesting its potential value as a therapeutic target. Keywords: Alzheimer’s disease; biomarkers; cerebrospinal fluid; inflammation; lipidomics.St. Josef's Hospital Fund, Reykjavik, Iceland Landspitali University Hospital Research Fund Icelandic Research Fund of the Icelandic Centre for Researc

Cartilage Acidic Protein 1 in Plasma Associates With Prevalent Osteoarthritis and Predicts Future Risk as Well as Progression to Joint Replacements : Results From the UK Biobank Resource

Funding Information: Supported by deCODE genetics/Amgen Inc. Publisher Copyright: © 2022 The Authors. Arthritis & Rheumatology published by Wiley Periodicals LLC on behalf of American College of Rheumatology.OBJECTIVE: The level of cartilage acidic protein 1 (CRTAC1) in plasma was recently discovered to be associated with osteoarthritis (OA) risk and progression to joint replacement in Iceland. This study was undertaken to validate these findings in an independent population. METHODS: In this study, 1,462 plasma proteins were measured in 54,265 participants from the UK Biobank on the Olink Explore platform. We analyzed the association of plasma proteins with prevalent OA, incident OA, and progression to joint replacement. We assessed the specificity of OA association through comparison of associations with inflammatory joint diseases and with previous joint replacement. RESULTS: The CRTAC1 protein showed the strongest association with prevalent knee OA (odds ratio [OR] 1.34 [95% confidence interval (95% CI) 1.27, 1.41]) and was associated with hip OA (OR 1.19 [95% CI 1.11, 1.28]). It predicted incident diagnosis of OA in the knee (hazard ratio [HR] 1.40 [95% CI 1.35, 1.46]) and hip (HR 1.25 [95% CI 1.19, 1.31]), as well as progression to joint replacement (HR 1.20 [95% CI 1.08, 1.33] for the knee and HR 1.22 [95% CI 1.08, 1.38] for the hip), while no association was found with inflammatory joint diseases. Individuals in the highest quintile of risk based on CRTAC1 level, age, sex, and body mass index had a 10-fold risk of knee or hip OA within 5 years compared to those in the lowest quintile. Adding aggrecan core protein (ACAN) and neurocan core protein (NCAN) to the model improved the prediction of OA but not joint replacement. Furthermore, we replicated the association of CUB domain-containing protein 1 with prior joint replacement. CONCLUSION: Plasma CRTAC1 is a specific biomarker for OA and a predictor of OA risk and progression to joint replacement. Adding ACAN and NCAN protein levels to the CRTAC1 model improved the prediction of OA.Peer reviewe

Obesity and risk of monoclonal gammopathy of undetermined significance and progression to multiple myeloma: a population-based study

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked FilesAll multiple myeloma (MM) cases are preceded by the premalignant state monoclonal gammopathy of undetermined significance (MGUS). Results from previous studies show a positive association between obesity and MM; however, the association between obesity and MGUS is controversial. The aims were to determine (1) if obesity is associated with an increased risk of MGUS and light-chain MGUS (LC-MGUS) and (2) whether obesity is associated with a higher risk of progression to MM and other lymphoproliferative (LP) diseases. Data from the population-based Age, Gene/Environment Susceptibility-Reykjavik Study (N = 5764) were used. We performed serum protein electrophoresis and serum free light-chain assay on all subjects to identify MGUS and LC-MGUS cases. We included 11 different measures on current and previous obesity in our analysis. Logistic regression and Cox proportional-hazard regression were used to analyze the associations. A total of 300 (5.2%) MGUS and 275 (4.8%) LC-MGUS cases were identified. During a median follow-up of 8 years, 18 had progressed to MM and 11 to other LP diseases. We found no association between the 11 obesity markers and MGUS or LC-MGUS (odds ratios 0.81 to 1.15 for all 11 variables in both conditions). Interestingly, we found that high midlife body mass index increased risk of progression to MM and other LP diseases (hazard ratio, 2.66; 95% confidence interval, 1.17-6.05). To conclude, obesity was not associated with MGUS. However, we found overweight/obesity to be a risk factor for progression from MGUS to MM and other LP diseases, suggesting that obesity plays a role in the transformation of MGUS to MM.National Institutes of Health, National Institute on Aging National Institute on Aging Intramural Research Program, a National Eye Institute Intramural Research Program Award National Institute on Deafness and Other Communication Disorders, Division of Scientific Programs Hjartavernd (the Icelandic Heart Association) Althingi (the Icelandic Parliament) University of Iceland Research Fund Icelandic Centre for Research (RANNIS) Landspitali University Hospital Research Fund Karolinska Instituted Foundations Marie Curie CIG National Cancer Institute, National Institutes of Healt

Bone disease in monoclonal gammopathy of undetermined significance: results from a screened population-based study

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked FilesPrevious studies have shown that individuals with monoclonal gammopathy of undetermined significance (MGUS) have an increased risk of fractures, although the underlying mechanisms remain unknown. Our aim was to analyze bone mineral density (BMD), bone volume, and risk of fractures among individuals with MGUS. We performed a screening using the Age, Gene/Environment Susceptibility (AGES)-Reykjavik Study cohort, consisting of 5764 elderly individuals, identifying 300 individuals with MGUS, and 275 with light-chain MGUS. Quantitative computerized tomography was performed in the lumbar spine and hip to evaluate BMD and bone geometry. Analysis of variance and the Tukey honest significance test were used to compare the groups. Hospital records were used to record fractures, with a mean follow-up of 6.9 years. Cox proportional hazard was used to compare fracture risk. No difference was found in BMD between subjects with MGUS and others in the spine (P = .34) or in total hip (P = .30). Individuals with MGUS had a significant increase in bone volume compared with others in the spine (P < .001) and total hip (P < .001). Overall, the risk of fractures was not significantly increased in individuals with MGUS (hazard ratio [HR], 1.19; 95% confidence interval [CI], 0.94-1.50). Men with MGUS had a significantly increased fracture risk, compared with other men (HR, 1.46; 95% CI, 1.03-2.08). Our results show that although individuals with MGUS do not have decreased BMD, bone volume is increased, and MGUS men have a 50% increased fracture risk. These results indicate that bone disease and fractures in MGUS differ from processes known from osteoporosis.University of Iceland Research Fund Icelandic Centre for Research (RANNIS) Landspitali University Hospital Research Fund Karolinska Institutet Foundations Marie Curie Career Integration Grants (CIG) National Institutes of Health, National Institute on Aging (NIA) NIA Intramural Research Program National Eye Institute National Institute on Deafness and Other Communication Disorders Division of Scientific Programs, Hjartavernd Althingi (the Icelandic Parliament) National Cancer Institute Memorial Sloan Kettering Cancer Center Icelandic National Bioethics Committe

Meta-analysis of erosive hand osteoarthritis identifies four common variants that associate with relatively large effect

[Abstract] Objectives: Erosive hand osteoarthritis (EHOA) is a severe subset of hand osteoarthritis (OA). It is unclear if EHOA is genetically different from other forms of OA. Sequence variants at ten loci have been associated with hand OA but none with EHOA. Methods: We performed meta-analysis of EHOA in 1484 cases and 550 680 controls, from 5 populations. To identify causal genes, we performed eQTL and plasma pQTL analyses, and developed one zebrafish mutant. We analysed associations of variants with other traits and estimated shared genetics between EHOA and other traits. Results: Four common sequence variants associated with EHOA, all with relatively high effect. Rs17013495 (SPP1/MEPE, OR=1.40, p=8.4×10-14) and rs11243284 (6p24.3, OR=1.35, p=4.2×10-11) have not been associated with OA, whereas rs11631127 (ALDH1A2, OR=1.46, p=7.1×10-18), and rs1800801 (MGP, OR=1.37, p=3.6×10-13) have previously been associated with hand OA. The association of rs1800801 (MGP) was consistent with a recessive mode of inheritance in contrast to its additive association with hand OA (OR homozygotes vs non-carriers=2.01, 95% CI 1.71 to 2.37). All four variants associated nominally with finger OA, although with substantially lower effect. We found shared genetic components between EHOA and other OA measures, grip strength, urate levels and gout, but not rheumatoid arthritis. We identified ALDH1A2, MGP and BMP6 as causal genes for EHOA, with loss-of-function Bmp6 zebrafish mutants displaying EHOA-like phenotypes. Conclusions: We report on significant genetic associations with EHOA. The results support the view of EHOA as a form of severe hand OA and partly separate it from OA in larger joints

Dietary intake is associated with risk of multiple myeloma and its precursor disease

Publisher's version (útgefin grein)The etiology of monoclonal gammopathy of undetermined significance (MGUS), the precursor state of multiple myeloma (MM), is mostly unknown and no studies have been conducted on the effect of diet on MGUS or progression from MGUS to MM. We aimed to explore the association between common foods and MGUS and progression to MM. Data from the population-based AGES Study (N = 5,764) were utilized. Food frequency questionnaire was used to assess dietary intake during adolescence, midlife, and late life. Serum protein electrophoresis and serum free light-chain assay was performed to identify MGUS (n = 300) and LC-MGUS cases (n = 275). We cross linked our data with the Icelandic Cancer Registry to find cases of MM in the study group. We found that intake of fruit at least three times per week during adolescence was associated with lower risk of MGUS when compared to lower fruit consumption (OR = 0.62, 95% CI 0.41–0.95). We additionally found that intake of fruit at least three times per week during the late life period was associated with decreased risk of progressing from MGUS to MM (HR = 0.34, 95% CI 0.13–0.89) when compared to lower intake. Adolescent intake of fruit may reduce risk of MGUS, whereas fruit intake after MGUS onset may reduce risk of progressing to MM. Our findings suggest that diet might alter the risk of developing MGUS and progression to MM.The AGES-Reykjavik Study was funded by NIH contract N01-AG-012100, the Intramural Research Program of the National Institute on Aging, by the Icelandic Heart Association, and the Icelandic Parliament. This work was supported by the Icelandic Centre for Research, RANNIS (S.Y. Kristinsson), the Landspitali University Hospital Research Fund (S.Y. Kristinsson), the Karolinska Instituted Foundations (S.Y. Kristinsson), the Marie Curie CIG (S.Y. Kristinsson), and the Memorial Sloan Kettering Core Grant (P30 CA008748) from the National Cancer Institute (O.Landgren). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer Reviewe