A man in his sixties with dyspnoea and oedema. / Mann i 60-årene med tungpustethet og ødemer.

BACKGROUND/CASE PRESENTATION: A man in his sixties with chronic obstructive pulmonary disease was hospitalised due to oedema and dyspnoea during the previous weeks. He was hypertensive, with 10 kg weight gain, generalised oedema, proximal myopathy and moon face. The assessment was consistent with ectopic ACTH-dependent Cushing's syndrome. A 15 mm lung tumour was detected on CT, with inconclusive cytological examination, and negative FDG/PET CT and octreotide scintigraphy. He developed necrotising pancreatitis and a duodenal perforation, which were surgically treated. His cortisol levels and Cushingoid appearance normalised after surgery, and it was concluded that his hypercortisolism was part of a physiological response. He remained clinically in habitual shape until two years later, when he again developed Cushingoid stigmata. A new octreotide scintigraphy was negative, but FDG/PET CT revealed increased FDG uptake in the lung lesion. Before a lung biopsy was performed, the patient developed necrotising pancreatitis. He was treated conservatively and died in respiratory failure. Autopsy revealed a NET in the lung and necrotising pancreatitis. INTERPRETATION: The case demonstrates diagnostic challenges in the assessment of ectopic ACTH-dependent cyclic Cushing's syndrome. Is also suggests that pancreatitis could be triggered by hypercortisolism.

Bone mineral density is associated with vitamin D related rs6013897 and estrogen receptor polymorphism rs4870044: The Tromsø study.

BACKGROUND: Bone mineral density (BMD) is determined by bone remodeling processes regulated by endocrine, autocrine and genetic mechanisms. Thus, some studies have reported that BMD is associated with single nucleotide polymorphisms (SNPs) associated with vitamin D receptor (VDR), serum 25(OH)D levels and estrogen receptor 1 (ESR1), but without consensus. Therefore, we aimed to map and compare the risk genotypes for forearm and total hip low BMD. METHODS AND FINDINGS: Data were derived from a population-based study in northern Norway; the Tromsø Study. Distal forearm BMD was measured with a single x-ray absorptiometric device, while total hip BMD was measured with a dual-energy x-ray absorptiometric device. There were 7,317 and 4,082 successful analyses of distal forearm and total hip BMD, respectively, and at least one SNP of interest. We evaluated plausible BMD modulating factors and associations of BMD and SNPs related to vitamin D metabolism (FokI, Cdx2, BsmI, rs2298850, rs10741657, rs3794060, rs6013897), ApaI-BsmI-TaqI haplotypes and ESR1 SNP rs4870044. RESULTS: Age, BMI, physical activity and smoking were significantly associated with BMD. In a linear regression model with adjustment for age and gender and with the major homozygote as reference, rs6013897 had a standardized beta coefficient (ß) of -0.031 (P = 0.024) for total hip BMD. ß for ESR1 SNP rs4870044 was -0.016 (P = 0.036) for forearm BMD and -0.034 (P = 0.015) for total hip BMD. The other SNPs nor serum 25(OH)D were significantly associated with BMD. CONCLUSIONS: Both forearm and total hip BMD were associated with ESR1 SNP rs4870044. Of the vitamin D-related genes, only CYP24A1 gene rs6013897 was associated with total hip BMD, but the association was weak and needs confirmation in other studies. Serum 25(OH)D was not associated with BMD in our population, probably due to the generally sufficient vitamin D levels in the population.

Correction: Genetic Variations in the Vitamin D Receptor Predict Type 2 Diabetes and Myocardial Infarction in a Community-Based Population: The Tromsø Study.

[This corrects the article DOI: 10.1371/journal.pone.0145359.].

Genetic Variations in the Vitamin D Receptor Predict Type 2 Diabetes and Myocardial Infarction in a Community-Based Population: The Tromsø Study.

BACKGROUND: Though the associations between low serum 25-hydroxyvitamin D (25(OH)D) levels and health outcomes such as type 2 diabetes (T2D), myocardial infarction (MI), cancer, and mortality are well-studied, the effect of supplementation with vitamin D is uncertain. This may be related to genetic differences. Thus, rs7968585, a single nucleotide polymorphism (SNP) of the vitamin D receptor (VDR), has recently been reported as a predictor of composite health outcome. We therefore aimed to evaluate whether rs7968585 predicts separate clinical outcomes such as T2D, MI, cancer, and mortality in a community-based Norwegian population. METHODS AND FINDINGS: Measurements and DNA were obtained from the participants in the Tromsø Study in 1994-1995, registered with the outcomes of interest and a randomly selected control group. The impact of the rs7968585 genotypes was evaluated with Cox proportional hazards. A total of 8,461 subjects were included among whom 1,054 subjects were registered with T2D, 2,287 with MI, 3,166 with cancer, and 4,336 with death. Mean follow-up time from birth was 60.8 years for T2D and MI, 61.2 years for cancer, while mean follow-up time from examination date was 16.5 years for survival. Mean serum 25(OH)D levels did not differ across the rs7968585 genotypes. With the major homozygote genotype as reference, the minor homozygote subjects had hazard ratios of 1.25 (95% CI 1.05-1.49) for T2D and 1.14 (1.02-1.28) for MI (P = 0.011 and 0.023, respectively, without the Bonferroni correction). No significant interaction between serum 25(OH)D status and the rs7968585 genotype was found for any of the endpoints. CONCLUSIONS: The VDR-related SNP rs7968585 minor allele is a significant and positive predictor for T2D and possibly for MI. Since the functional mechanism of this SNP is not yet understood, and the association with T2D is reported for the first time, confirmatory studies are needed.

The DBP Phenotype Gc-1f/Gc-1f Is Associated with Reduced Risk of Cancer. The Tromsø Study.

BACKGROUND AND OBJECTIVE: In addition to its role as a transport protein, the vitamin D binding protein (DBP) may also affect lipid metabolism, inflammation and carcinogenesis. There are three common variants of the DBP, Gc1s (1s), Gc1f (1f), Gc2 (2) that result in six common phenotypes (1s/1s, 1s/1f, 1s/2, 1f/1f, 1f/2, and 2/2). These phenotypes can be identified by genotyping for the two single nucleotide polymorphisms rs7041 and rs4588 in the GC gene. The DBP variants have different binding coefficients for the vitamin D metabolites, and accordingly there may be important relations between DBP phenotypes and health. METHODS: DNA was prepared from subjects who participated in the fourth survey of the Tromsø Study in 1994-1995 and who were registered with the endpoints myocardial infarction (MI), type 2 diabetes (T2DM), cancer or death as well as a randomly selected control group. The endpoint registers were complete up to 2010- 2013. Genotyping was performed for rs7041 and rs4588 and serum 25-hydroxyvitamin D (25(OH)D) was measured. RESULTS: Genotyping for rs7041 and rs4588 was performed successfully in 11 704 subjects. Among these, 1660 were registered with incident MI, 958 with T2DM, 2410 with cancer and 4318 had died. Subjects with the DBP phenotype 1f/1f had 23 - 26 % reduced risk of incident cancer compared to the 1s/1s and 2/2 phenotypes (P < 0.02, Cox regression with gender as covariate). Differences in serum 25(OH)D levels could not explain the apparent cancer protective effect of the DBP variant 1f. In addition to cancer and 25(OH)D, there were significant associations between DBP phenotype and body height, hip circumference and serum calcium. CONCLUSION: There are important biological differences between the common DBP phenotypes. If the relation between the DBP variant 1f and cancer is confirmed in other studies, determination of DBP phenotype may have clinical importance.

High-sensitivity C-reactive protein is an independent risk factor for non-vertebral fractures in women and men: The Tromsø Study.

Low-grade inflammation is associated with fractures, while the relationship between inflammation and bone mineral density (BMD) is less clear. Moreover, any gender differences in the sensitivity to inflammation are still poorly elucidated. We therefore tested the hypothesis that high-sensitivity C-reactive protein (CRP) is an independent risk factor for low BMD and non-vertebral fractures, in both genders, and whether there are gender differences in these associations. CRP levels and BMD at the total hip and femoral neck were measured in 1902 women and 1648 men between 55 and 74 years of age, at baseline in the Tromsø Study, Norway, in 2001-2002. Non-vertebral fractures were registered from hospital X-ray archives during an average of 7.2 years follow-up. Linear regression analyses were used for CRP association with BMD and Cox proportional hazards model for fracture prediction by CRP. During 25 595 person-years follow-up, 366 (19%) women and 126 (8%) men suffered a non-vertebral fracture. There was no association between CRP and BMD in women, but an inverse association in men (p=0.001) after adjustment for age and body mass index. Each standard deviation (SD) increase in log-CRP was associated with an increased risk for non-vertebral fracture by 13% in women and 22% in men (hazard ratios (HRs) 1.13, 95% confidence interval (CI) 1.02-1.26, p=0.026 and 1.22, 95% CI=1.00-1.48, p=0.046, respectively). After adjustment for BMD and other risk factors, women with CRP in the upper tertile exhibited 39% higher risk for fracture than those in the lowest tertile of CRP (HR = 1.39, 95% CI = 1.06-1.83, p = 0.017), while men in the upper tertile exhibited 80% higher risk (HR=1.80, 95% CI=1.10-2.94, p=0.019). In summary, CRP was not associated with BMD in women but inversely associated in men, and predicted fractures in both genders. We infer that inflammation influence fracture risk in both women and men, although the biological mechanisms may differ between the genders.

The phosphodiesterase 8B gene rs4704397 is associated with thyroid function, risk of myocardial infarction, and body height: the Tromsø study.

OBJECTIVE: High serum thyrotropin (TSH) levels predict cardiovascular disease (CVD). Recently several single nucleotide polymorphisms (SNPs) associated with TSH levels have been identified, one of them being the rs4704397 SNP in the phosphodiesterase 8B (PDE8B) gene. If the relation between thyroid function and CVD is causal, one could also expect rs4704397 genotypes to predict CVD and possibly health in general. METHODS: DNA was prepared and genotyping performed for rs4704397 in subjects who participated in the fourth survey of the Tromsø Study in 1994-1995 and who were registered with the endpoints myocardial infarction (MI), type 2 diabetes (T2DM), cancer, or death, as well as a randomly selected control group. Similarly, genotyping was performed in subjects who had participated in clinical trials where serum TSH, free T4 (fT4), and free T3 (fT3) were measured. RESULTS: From the Tromsø Study, 8938 subjects without thyroid disease or thyroid medication were successfully genotyped for rs4704397. Among these, 2098 were registered with MI, 1025 with T2DM, 2748 with cancer, and 3592 had died. The minor homozygote genotype (A:A) had a median serum TSH level that was 0.29 mIU/L higher than in the major homozygote genotype (G:G). The A:A genotype had a significantly increased risk of MI as compared to the G:G genotype (1.14 [1.00-1.29], hazard ratio [confidence interval], Cox regression with adjustment for age, sex, and body mass index). No significant associations were seen with the other endpoints or CVD risk factors. Furthermore, subjects with the G:G genotype were significantly taller than subjects with the A:A genotype (mean difference 1.5 cm). In 584 subjects with serum TSH, fT4, and fT3 measurements, the subjects with the A:A genotype had significantly higher serum TSH and nonsignificantly lower serum fT3 (mean difference 0.15 pmol/L) levels than subjects with the G:G genotype. CONCLUSION: rs4704397 is associated with thyroid function, risk of MI, and body height. However, confirmation in other cohorts is needed before firm conclusions can be drawn.

Effects of Age and Sex on Estimated Diabetes Prevalence Using Different Diagnostic Criteria: The Tromsø OGTT Study.

HbA(1c) 6.5% has recently been recommended as an alternative diagnostic criterion for diabetes. The aims of the study were to evaluate the effects of age, sex, and other factors on prevalence of diabetes and to compare risk profiles of subjects with diabetes when defined by HbA(1c) and glucose criteria. Subjects were recruited among participants in the longitudinal population-based Tromsø Study. HbA(1c), fasting plasma glucose, and 2-hour plasma glucose were measured in 3,476 subjects. In total, 294 subjects met one or more of the diagnostic criteria for diabetes; 95 met the HbA(1c) criterion only, 130 met the glucose criteria only, and 69 met both. Among subjects with diabetes detected by glucose criteria (regardless of HbA(1c)), isolated raised 2-hour plasma glucose was more common in subjects aged ≥ 60 years as compared to younger subjects and in elderly women as compared to elderly men. Subjects with diabetes detected by glucose criteria only had worse cardiometabolic risk profiles than those detected by HbA(1c) only. In conclusion, the current HbA(1c) and glucose criteria defined different subjects with diabetes with only modest overlap. Among a substantial proportion of elderly subjects, and especially elderly women, the 2-hour plasma glucose was the only abnormal value.

Polymorphisms related to the serum 25-hydroxyvitamin D level and risk of myocardial infarction, diabetes, cancer and mortality. The Tromsø Study.

OBJECTIVE: Low serum 25(OH)D levels are associated with cardiovascular risk factors, and also predict future myocardial infarction (MI), type 2 diabetes (T2DM), cancer and all-cause mortality. Recently several single nucleotide polymorphisms (SNPs) associated with serum 25-hydroxyvitamin D (25(OH)D) level have been identified. If these relations are causal one would expect a similar association between these SNPs and health. METHODS: DNA was prepared from subjects who participated in the fourth survey of the Tromsø Study in 1994-1995 and who were registered with the endpoints MI, T2DM, cancer or death as well as a randomly selected control group. The endpoint registers were complete up to 2007-2010. Genotyping was performed for 17 SNPs related to the serum 25(OH)D level. RESULTS: A total of 9528 subjects were selected for genetic analyses which were successfully performed for at least one SNP in 9471 subjects. Among these, 2025 were registered with MI, 1092 with T2DM, 2924 with cancer and 3828 had died. The mean differences in serum 25(OH)D levels between SNP genotypes with the lowest and highest serum 25(OH)D levels varied from 0.1 to 7.8 nmol/L. A genotype score based on weighted risk alleles regarding low serum 25(OH)D levels was established. There was no consistent association between the genotype score or individuals SNPs and MI, T2DM, cancer, mortality or risk factors for disease. However, for rs6013897 genotypes (located at the 24-hydroxylase gene (CYP24A1)) there was a significant association with breast cancer (P<0.05). CONCLUSION: Our results do not support nor exclude a causal relationship between serum 25(OH)D levels and MI, T2DM, cancer or mortality, and our observation on breast cancer needs confirmation. Further genetic studies are warranted, particularly in populations with vitamin D deficiency. TRIAL REGISTRATION: ClinicalTrials.gov NCT01395303.

Plasma profile of microRNA after supplementation with high doses of vitamin D3 for 12 months.

BACKGROUND: Recently a large number of short non-coding-RNAs (microRNAs, (miRNA)) have been identified. These miRNAs act as post-transcriptional regulators where they generally have an inhibitory function. miRNAs are present in all human cells, and they are also detected in serum or plasma. The miRNAs have a broad range of actions, and their biogenesis must therefore be under tight control. One putative regulator of miRNA biogenesis or miRNA level could be vitamin D, an ancient hormone with effects on cell growth and differentiation, apoptosis and the immune system. In our study miRNA were reversed transcribed in total RNA isolated from plasma and analyzed by quantitative real-time PCR (qPCR) using the miRCURY LNA Universal RT microRNA PCR system (Exiqon). In 10 pilot subjects 136 miRNAs were detected in one or more plasma samples drawn at baseline and after 12 months of vitamin D supplementation. The twelve miRNAs that showed the greatest change in expression in these pilots were further analyzed by RT-qPCR of RNA from baseline and 12 months plasma samples in 40 subjects given high dose vitamin D(3) (20.000-40.000 IU per week) and 37 subjects given placebo. RESULTS: At baseline there was a significant and positive correlation between serum 25-hydroxyvitamin D and miR-532-3p expression (r = 0.24, P = 0.04). The change in expression of miR-221 from baseline to 12 months (ddCp value) was also significantly different between the vitamin D and placebo group (P =0.04), mainly due to a change in the placebo group. CONCLUSIONS: We have not been able to demonstrate a consistent effect of vitamin D supplementation on the expression profile of miRNA in plasma. However, further studies are needed as this approach might potentially throw light on unknown aspects of vitamin D physiology.

Associations between polymorphisms related to calcium metabolism and human height: the Tromsø Study.

A number of single nucleotide polymorphisms (SNPs) related to height have been detected. Calcium metabolism is important for the skeleton and accordingly also for adult height. Therefore, in the present study, nine SNPs related to the vitamin D receptor (VDR) gene and serum levels of 25-hydroxyvitamin D (25(OH)D), calcium, phosphate and parathyroid hormone (PTH) were related to height in 9471 subjects. Relation with height was evaluated with linear regression for trend across SNP genotypes with age and gender as covariates. After correcting for multiple testing, significant associations with height were found for two SNPs related to the VDR gene (rs1544410 (Bsml) and rs7975232 (Apal)), one SNP related to serum 25(OH)D (rs3829251 at the DHCR7/NADSYN1 gene), one SNP related to serum calcium (rs1459015 at the PTH gene) and one SNP related to serum phosphate (rs1697421 at the ALPL gene). For rs3829251, the mean differences in height between major and minor homozygotes were 1.5-2.0 cm (P < 0.01) and were seen in both genders and all age groups tested, whereas for the other SNPs, the differences were less than 1 cm. In conclusion, several SNPs related to calcium metabolism are associated with height, in particular rs3829251 at the DHCR7/NADSYN1 gene.

Low serum 25-hydroxyvitamin D levels are associated with increased all-cause mortality risk in a general population: the Tromsø study.

OBJECTIVE: Ecologic and observational studies have suggested an association between serum 25-hydroxyvitamin D (25(OH)D) levels and cardiovascular disease (CVD) risk factors, CVD mortality, and cancer mortality. Based on this, low serum 25(OH)D levels should be associated with higher all-cause mortality in a general population. This hypothesis was tested in the present study. DESIGN: The Tromsø study is a longitudinal population-based multipurpose study initiated in 1974 with focus on lifestyle-related diseases. Our data are based on the fourth Tromsø study carried out in 1994-1995. METHODS: Information about death and cause of death was registered by obtaining information from the National Directory of Residents and the Death Cause Registry. Serum 25(OH)D was measured in 7161 participants in the fourth Tromsø study. Results are presented for smokers (n=2410) and non-smokers (n=4751) separately as our immunoassay seems to overestimate 25(OH)D levels for smokers. RESULTS: During a mean 11.7 years of follow-up, 1359 (19.0%) participants died. In multivariate regression models, there was a significantly increased risk of all-cause mortality (hazard ratio (HR) 1.32, confidence interval (CI) 1.07-1.62) among non-smoking participants in the lowest 25(OH)D quartile when compared with participants in the highest quartile. Equivalent results for smokers were not significant (HR 1.06, CI 0.83-1.35). CONCLUSIONS: Low serum 25(OH)D levels were associated with increased all-cause mortality for non-smokers, but the results did not reach statistical significance for smokers. However, low 25(OH)D levels are known to be associated with impaired general health, and randomized controlled studies are needed to address the question of causality.

Lifestyle impact on lifetime bone loss in women and men: the Tromsø Study.

A physically active, nonsmoking lifestyle with weight maintenance positively influences bone health. The authors estimated the effect of lifestyles on peak bone mass and lifetime bone loss in the Tromsø Study, Norway. Bone mineral density (BMD) was measured at distal and ultradistal forearm sites with single x-ray absorptiometric devices in 7,948 men and women aged 24-84 years in 1994-1995 and repeated in 2001 in 6,182 subjects. BMD was significantly higher at peak than at old age. However, the difference, estimated as lifetime loss, varied between lifestyle groups. Lifetime loss in nonsmoking, physically active men with a body mass index of 25 kg/m(2) compared with smoking, inactive, and lean men was 15.9% and 25.9% at the distal site and 17.5% and 29.7% at the ultradistal site, respectively. In women, the corresponding loss estimates were 34.4% and 45.7% and 35.6% and 55.7%, respectively. The differences in BMD at the age of 80 years correspond to an increased forearm fracture risk of 69% in men and 85% in women with greatest bone loss. A lifestyle including nonsmoking, a high physical activity level, and a high body weight reduces bone loss and fracture risk in both sexes, with increasing effect from peak bone mass to old age.

The relationship between serum TSH and bone mineral density in men and postmenopausal women: the Tromsø study.

BACKGROUND: Hyperthyroidism is associated with osteoporosis, and it has recently been suggested that thyroid-stimulating hormone (TSH) has bone protective properties. We wanted to explore the relationship between serum TSH and bone mineral density (BMD) in a healthy population. METHODS: This study included 993 postmenopausal females and 968 males with valid measurements of BMD at the hip and forearm in the fifth Tromsø study conducted in 2001. Participants with major diseases or medication affecting BMD or thyroid function were excluded. The subjects were divided into six different groups based on the 2.5 and 97.5 percentiles of serum TSH and the quartiles in between. Multiple linear regression adjusting for age; weight; height; smoking status; physical activity level; and for women, use of hormonal replacement therapy was used in the analyses. RESULTS: After multivariate adjustment, the 28 men and 18 women with serum TSH below the 2.5 percentile had significantly lower BMD at the ultradistal (women) and distal (both sexes) forearm than the 921 men and 950 women with serum TSH in the normal range. Also, the 25 postmenopausal women with serum TSH above the 97.5 percentile had significantly higher BMD at the femoral neck than women with serum TSH in the normal range. Across the normal range of serum TSH, there was no association between TSH and BMD, and serum TSH as a continuous variable had no effect on BMD in the multiple linear regression model. CONCLUSIONS: Within the normal range of serum TSH, serum TSH was not associated with BMD. The small groups of men and women with serum TSH consistent with hyperthyroidism had lower BMD at the forearm than those with serum TSH in the normal range.

The association between serum parathyroid hormone and bone mineral density, and the impact of smoking: the Tromso Study.

OBJECTIVE: To explore the relation between serum parathyroid hormone (PTH) and bone mineral density (BMD), adjusted for lifestyle factors including smoking. DESIGN: Cross-sectional study. METHODS: The Tromsø Study is a population-based study performed for the fifth time in 2001. Serum PTH was measured and the subjects filled in a questionnaire covering lifestyle factors. BMD at the hip, distal and ultradistal forearm was measured. RESULTS: Complete datasets were available in 1442 men and 1368 women. Age, body mass index and serum PTH were strong predictors of BMD level at the hip in both genders. No significant relation was seen between serum PTH and BMD at the distal or ultradistal forearm. When smokers and non-smokers were analysed separately, the relation between PTH and BMD at the hip was significant in current non-smokers only. In males, current non-smokers had significantly higher BMD at all three measurement sites compared with current smokers. Male former smokers had values in between current and never smokers. There was a significant and negative relation between number of years smoked and BMD at the hip. In male former smokers, there was an increase in BMD with increasing years since smoking cessation. CONCLUSION: Serum PTH is negatively associated with BMD at the hip, and the relation seems to be masked, or diminished, by smoking. Smoking reduces BMD at the hip, distal and ultradistal forearm in males, and the effect appears to be mainly time and not dose dependent.

A prospective study of sex steroids, sex hormone-binding globulin, and non-vertebral fractures in women and men: the Tromso Study.

OBJECTIVES: As bone fragility is partly the result of sex hormone deficiency, we sought to determine whether circulating sex steroids or sex hormone-binding globulin (SHBG) predicts non-vertebral fractures. METHODS: Forearm bone mineral density (BMD), total estradiol and testosterone, calculated free levels, and SHBG were measured in 1386 postmenopausal women and 1364 men aged 50-84 years at baseline in the Tromsø Study (1994-1995). Non-vertebral fractures were documented between 1994 and 2005. RESULTS: During 8.4 years (range 0.01-10.4) of follow-up, 281 women and 105 men suffered non-vertebral fractures. For both sexes, fracture cases had lower BMD and higher SHBG, but sex steroids were not lower. Each standard deviation (s.d.) increase in SHBG increased non-vertebral fracture risk in women (hazards ratio (HR) 1.17; 95% confidence interval (CI) 1.03-1.33) and men (HR 1.26; 95% CI 1.03-1.54). After further adjustment for BMD, the risk was not statistically significant in women (HR 1.09; 95% CI 0.95-1.24) or men (HR 1.22; 95% CI 0.99-1.49). Each s.d. decrease in BMD increased fracture risk in women (HR 1.36; 95% CI 1.19-1.56) and men (HR 1.41; 95% CI 1.15-1.73). Fracture rates were highest in participants with SHBG in the highest tertile and BMD in the lowest tertile and were 37.9 and 17.0 per 1000 person-years in women and men respectively. However, in both sexes the combination of BMD and SHBG was no better predictor of fracture risk than BMD alone. Sex steroids were not associated with fracture risk. CONCLUSIONS: Measurements of sex steroids or SHBG are unlikely to assist in decision making regarding fracture risk susceptibility.