| 1. |
- Loseth, Sissel, et al.
(författare)
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Polyneuropathy in type 1 and type 2 diabetes : comparison of nerve conduction studies, thermal perception thresholds and intraepidermal nerve fibre densities
- 2010
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Ingår i: Diabetes/Metabolism Research Reviews. - : Wiley. - 1520-7552 .- 1520-7560. ; 26:2, s. 100-106
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Tidskriftsartikel (refereegranskat)abstract
- Background To evaluate possible differences in distal polyneuropathy (PN) characteristics and degree of abnormalities for various small and large fibre parameters in diabetes type 1 (DM1) and type 2 (DM2). Methods Sixty-six DM1 and 57 DM2 patients with or without PN symptoms were included. Nerve conduction studies (NCS), quantitative sensory testing (QST) and quantification of intraepidermal nerve fibres (IENFs) were performed. Z-scores were calculated from reference materials. Results In both groups, 42% had abnormal NCS classification, 42% (DM1) and 39% (DM2) abnormal QST, as well as 40% (DM1) and 32% (DM2) abnormal IENF density. Seventy percent (DM1) and 65% (DM2) had one of the three tests abnormal (differences not significant). Correlations were found between most Z-score parameters and disease duration and HbAlc in DM1, but fewer in DM2. In multivariate analysis, some NCS and QST Z-scores were more abnormal in DM2. Symptom scoring correlated better with NCS and QST parameters in DM1. Conclusions The differences could be referred to disease duration, glycaemic control and possibly patient age. The various parameters from NCS, QST and IENF analysis contribute differently in the assessment of polyneuropathy. Copyright (C) 2009 John Wiley & Sons, Ltd.
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| 2. |
- Løseth, Sissel, et al.
(författare)
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Early diabetic neuropathy : thermal thresholds and intraepidermal nerve fibre density in patients with normal nerve conduction studies.
- 2008
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Ingår i: Journal of Neurology. - : Springer Science and Business Media LLC. - 0340-5354 .- 1432-1459. ; 255:8, s. 1197-1202
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES To determine whether neuropathy in diabetic patients with normal nerve conduction studies could be detected by measurements of thermal thresholds and quantification of intraepidermal nerve fibre (IENF) density, and to evaluate differences in parameters between patients with and without neuropathic symptoms. METHODS A total of 22 patients with and 37 patients without sensory symptoms suggesting distal neuropathy were included. Measurements of warm and cold perception thresholds and skin biopsy for quantification of IENFs were performed distally on the leg. Reference data were used to normalize test results for age and height or gender of individual patients by calculating the Z-scores. RESULTS IENF density was significantly reduced in both symptomatic and asymptomatic patients compared to controls (p < 0.001), and in patients with symptoms compared to those without (p = 0.01). Thermal thresholds were significantly elevated (more abnormal) in patients with symptoms compared to controls (p < 0.01), but only for cold perception threshold (CPT) (p < 0.001) in the asymptomatic group. When comparing symptomatic and asymptomatic patients, there was no statistically significant difference in thermal thresholds. Depletion of IENFs in skin biopsy was the most frequent abnormal finding in the subgroup of patients with neuropathic symptoms (36 %) followed by abnormal CPT (27 %). CONCLUSION Patients with diabetes and normal nerve conduction studies had significantly lower IENF density and higher CPT than controls, whether they had symptoms of polyneuropathy or not. In patients with neuropathic symptoms, abnormal IENF density predominated and seemed thus to be the most sensitive tool of detecting small diameter nerve fibre involvement.
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| 3. |
- Løseth, Sissel, et al.
(författare)
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Small and large fiber neuropathy in those with type 1 and type 2 diabetes : a 5-year follow-up study
- 2016
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Ingår i: Journal of the peripheral nervous system. - : Wiley. - 1085-9489 .- 1529-8027. ; 21:1, s. 15-21
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study was to evaluate progression of diabetic polyneuropathy and differences in the spectrum and evolution of large- and small-fiber involvement in patients with diabetes type 1 and 2 over 5 years. Fifty-nine patients (35 type 1 and 24 type 2) were included. Nerve conduction studies (NCS), quantitative sensory testing, skin biopsy for quantification of intraepidermal nerve fiber density (IENFD), symptom scoring and clinical evaluations were performed. Z-scores were calculated to adjust for the physiologic effects of age and height/gender. Neuropathic symptoms were not significantly more frequent in type 2 than in type 1 diabetic patients at follow-up (54% vs. 37%). The overall mean NCS Z-score remained within the normal range, but there was a small significant decline after 5 years in both groups: type 1 (p = 0.004) and type 2 (p = 0.02). Mean IENFD Z-scores changed from normal to abnormal in both groups, but only significantly in those with type 2 diabetes (reduction from 7.9 +/- 4.8 to 4.3 +/- 2.8 fibers/mm, p = 0.006). Cold perception threshold became more abnormal only in those with type 2 diabetes (p = 0.049). There was a minimal progression of large fiber neuropathy in both groups. Reduction of small fibers predominated and progressed more rapidly in those with type 2 diabetes.
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| 4. |
- Maddock, Jane, et al.
(författare)
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Vitamin D and cognitive function : A Mendelian randomisation study.
- 2017
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- The causal nature of the association between hypovitaminosis D and poor cognitive function in mid- to later-life is uncertain. Using a Mendelian randomisation(MR) approach, we examined the causal relationship between 25(OH)D and cognitive function. Data came from 172,349 participants from 17 cohorts. DHCR7(rs12785878), CYP2R1 rs12794714) and their combined synthesis score were chosen to proxy 25(OH)D. Cognitive tests were standardised into global and memory scores. Analyses were stratified by 25(OH)D tertiles, sex and age. Random effects meta-analyses assessed associations between 25(OH)D and cognitive function. Associations of serum 25(OH)D with global and memory-related cognitive function were non-linear (lower cognitive scores for both low and high 25(OH)D, p curvature ≤ 0.006), with much of the curvature attributed to a single study. DHCR7, CYP2R1, and the synthesis score were associated with small reductions in 25(OH)D per vitamin D-decreasing allele. However, coefficients for associations with global or memory-related cognitive function were non-significant and in opposing directions for DHCR7 and CYP2R1, with no overall association observed for the synthesis score. Coefficients for the synthesis score and global and memory cognition were similar when stratified by 25(OH)D tertiles, sex and age. We found no evidence for serum 25(OH)D concentration as a causal factor for cognitive performance in mid- to later life.
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| 5. |
- Vimaleswaran, Karani S, et al.
(författare)
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Association of vitamin D status with arterial blood pressure and hypertension risk: a mendelian randomisation study.
- 2014
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Ingår i: The lancet. Diabetes & endocrinology. - 2213-8595 .- 2213-8587. ; 2:9, s. 719-29
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Tidskriftsartikel (refereegranskat)abstract
- Background Low plasma 25-hydroxyvitamin D (25[OH]D) concentration is associated with high arterial blood pressure and hypertension risk, but whether this association is causal is unknown. We used a mendelian randomisation approach to test whether 25(OH)D concentration is causally associated with blood pressure and hypertension risk. Methods In this mendelian randomisation study, we generated an allele score (25[OH]D synthesis score) based on variants of genes that affect 25(OH)D synthesis or substrate availability (CYP2R1 and DHCR7), which we used as a proxy for 25(OH)D concentration. We meta-analysed data for up to 108173 individuals from 35 studies in the D-CarDia collaboration to investigate associations between the allele score and blood pressure measurements. We complemented these analyses with previously published summary statistics from the International Consortium on Blood Pressure (ICBP), the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium, and the Global Blood Pressure Genetics (Global BPGen) consortium. Findings In phenotypic analyses (up to n=49363), increased 25(OH)D concentration was associated with decreased systolic blood pressure (β per 10% increase, −0·12 mm Hg, 95% CI −0·20 to −0·04; p=0·003) and reduced odds of hypertension (odds ratio [OR] 0·98, 95% CI 0·97–0·99; p=0·0003), but not with decreased diastolic blood pressure (β per 10% increase, −0·02 mm Hg, −0·08 to 0·03; p=0·37). In meta-analyses in which we combined data from D-CarDia and the ICBP (n=146581, after exclusion of overlapping studies), each 25(OH)D-increasing allele of the synthesis score was associated with a change of −0·10 mm Hg in systolic blood pressure (−0·21 to −0·0001; p=0·0498) and a change of −0·08 mm Hg in diastolic blood pressure (−0·15 to −0·02; p=0·01). When D-CarDia and consortia data for hypertension were meta-analysed together (n=142255), the synthesis score was associated with a reduced odds of hypertension (OR per allele, 0·98, 0·96–0·99; p=0·001). In instrumental variable analysis, each 10% increase in genetically instrumented 25(OH)D concentration was associated with a change of −0·29 mm Hg in diastolic blood pressure (−0·52 to −0·07; p=0·01), a change of −0·37 mm Hg in systolic blood pressure (−0·73 to 0·003; p=0·052), and an 8·1% decreased odds of hypertension (OR 0·92, 0·87–0·97; p=0·002). Interpretation Increased plasma concentrations of 25(OH)D might reduce the risk of hypertension. This finding warrants further investigation in an independent, similarly powered study.
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