Background Parathyroidectomy has ameliorated cardiovascular risk factors in patients with hypercalcemic primary hyperparathyroidism (PHPT), but the effect of parathyroidectomy on normocalcemic PHPT is not exactly known. This case-controlled study aimed to investigate the effect of parathyroidectomy on cardiovascular risk factors in patients with normocalcemic and hypercalcemic PHPT. Methods Subjects with normocalcemic PHPT ( n = 35), age- and sex-matched hypercalcemic PHPT ( n = 60) and age- and sex-matched control ( n = 60) were included. Cardiometabolic disorders were investigated with traditional cardiometabolic risk factors and the Framingham cardiovascular risk score (CRS) before and 6 months after parathyroidectomy. Results Diabetes, dyslipidemia, hypertension, obesity, insulin resistance, osteoporosis, having fractures were similarly increased in the hypercalcemic and normocalcemic PHPT groups ( p > 0.05) compared with the controls ( p < 0.05). Blood pressures, glucose metabolism (glucose, insulin, HOMA-IR) and lipid profiles were similarly increased in the PHPT groups ( p > 0.05) compared with the controls ( p < 0.05). After parathyroidectomy, blood pressures, serum total cholesterol, and HOMA-IR were decreased in both PHPT groups ( p < 0.05). CRS was lower in the controls (5.74 ± 3.24, p < 0.05). After parathyroidectomy, CRS was decreased in the normocalcemic (11.98 ± 10.11 vs. 7.37 ± 4.48) and hypercalcemic (14.62 ± 11.06 vs. 8.05 ± 7.72) PHPT groups. Increased blood pressures were independent predictors of serum iPTH. Conclusion The normocalcemic and hypercalcemic PHPT groups had similarly increased cardiovascular risk factors, even independently of serum calcium. Parathyroidectomy ameliorated the increased cardiovascular risk factors in both normocalcemic and hypercalcemic PHPT.

IntroductionVitamin D deficiency is a common health problem. Vitamin D supplements are used to improve vitamin D status; however, there are contradictory data related to what doses to give and how often they should be given. Many studies have investigated the effects of vitamin D supplementation on muscle strength, but the results remain controversial. We aimed to compare the effects and safety of single high-dose with daily low-dose oral colecalciferol on 25(OH)D levels and muscle strength in postmenopausal women with vitamin D deficiency or insufficiency.Methods and designSixty healthy postmenopausal women who had serum vitamin D levels < 20 ng/mL (50 nmol/L) were enrolled in the study. Group 1 (n = 32) was given daily oral dosages of 800 IU vitamin D3, and group 2 (n = 28) was given a single oral dose of 300,000 IU vitamin D3. Serum vitamin D levels and muscle strengths were measured at the beginning, 4th, and 12th week. Muscle strength tests were performed at 60° using a Biodex system 3 isokinetic dynamometer.ResultsPretreatment vitamin D levels did not differ between the two groups (10.2 ± 4.4 ng/mL (25,4 ± 10,9 nmol/L); 9.7 ± 4.4 ng/mL (24,2 ± 10,9 nmol/L), p > 0.05). A significant increase in vitamin D levels was observed in both groups at 4 and 12 weeks after vitamin D3 treatment. The increase in the single-dose group was significantly higher than the daily low-dosage group at the 4th week (35.9 ± 9.6 ng/mL (89,6 ± 23,9 nmol/L), 16.9 ± 5.8 ng/mL (42,1 ± 14,4 nmol/L), p = 0.01). The increase in the single-dose group was significantly higher than in the daily low dosage group at the 12th week (23.4 ± 4.7 ng/mL (58,4 ± 11,7 nmol/L), 19.8 ± 7.2 ng/mL (49,4 ± 17,9 nmol/L), p = 0.049). The quadriceps muscle strength score increased significantly in the daily group at the 4th week (p = 0.038). The hamstring muscle strength score increased significantly in the daily group at the 12th week (p = 0.037).ConclusionAlthough daily administration routes are more effective in improving muscle strength, a single administration is more effective in increasing vitamin D levels.Trial registration numberISRCTN14226530 (04.07.2018), Name of the registry: ISRCTN registry, The study was retrospectively registered.

As a consequence of the presence of VDR and 1α-hydroxylase in different parts of the eye, vitamin D replacement improves tear hyperosmolarity that is considered to be induced by ocular surface inflammation.

This is the first study to investigate the effect of vitamin D receptor (VDR) gene single-nucleotide polymorphisms on the clinicopathologic features of papillary thyroid cancer in Turkey. A total of 165 patients with papillary thyroid cancer and 172 controls were included in this case-control study. VDR gene single-nucleotide polymorphisms FokI (rs2228570), BsmI (rs1544410), ApaI (rs7975232), and TaqI (rs731236) were evaluated using reverse-transcription polymerase chain reaction. VDR gene polymorphisms BsmI, ApaI, and TaqI did not differ between the papillary thyroid cancer group and control group (p. 0.05, each). BsmI, ApaI, and TaqI were not associated with papillary thyroid cancer risk. The VDR gene FokI CT/TT genotype was associated with an increased papillary thyroid cancer risk (CT vs CC: odds ratio = 1.71, 95% confidence interval = 1.15-2.76, p = 0.028; TT vs CC: odds ratio = 2.44, 95% confidence interval = 1.29-4.62, p = 0.005; CT/TT vs CC: odds ratio = 1.88, 95% confidence interval = 1.20-2.96, p = 0.006; CT/CC vs TT: odds ratio = 1.80, 95% confidence interval = 1.05-3.20, p = 0.041). VDR gene polymorphisms were not in linkage disequilibrium. The FokI TT genotype was associated with having T3 and T4, stage III/IV, extra-thyroidal invasion. The FokI CT/TT or TT genotype was associated with developing N1 status, multifocality, tumor size ø 10 mm, and treatment with radioiodine therapy. Persistence/recurrence did not differ between the FokI genotypes. Carriers of the FokI T allele were at an increased risk of more advanced tumor-node-metastasis stage, greater tumor size, multifocality, and extrathyroidal invasion of papillary thyroid cancer compared with the CC genotype. VDR gene FokI T allele and TT genotype correlated with aggressiveness of papillary thyroid cancer; thus, FokI could be useful as a poor prognostic factor to assess the high risk of papillary thyroid cancer.

Lactogens comprise three closely related peptide hormones: human growth hormone (hGH), human placental lactogen (hPL), and human prolactin (hPRL). hPRL and hGH originate from the pituitary and hPL is secreted by syncytiotrophoblasts of the placenta. Levels of hPL vary during pregnancy; it can be detected from the sixth week of gestation, increases steadily in the first and second trimesters, and peaks at a constant level in the third. hPL expression has been reported in testicular, ovarian, and breast cancers. Of the endocrine tumors, differentiated thyroid cancer (DTC) is the most frequently seen and commonly occurs in younger women and pregnancy has the potential to exacerbate thyroid cancer progression or recurrence. Although hGH binds well to GH receptors (GHR) and PRL receptors (PRLR), hPRL only binds to PRLR. hPL per se has no specific receptor yet it is able to bind to PRLRs with a high affinity regardless of its low (23%) structural homology to PRL. Paradoxically, hPL binds weakly to GHR even though they have significant (85%) amino acid sequence homology. We hypothesized that high levels of hPL could explain the worse outcomes of DTC in pregnancy. A possible mechanism could be that hPL binds GHR-PRLR in thyroid tissue and promotes tumor growth. Alternatively, the high affinity of hPL for PRLRs expressed in thyroid cancer may account for these results. Conversely, hPL binding to GHR, albeit weakly, might also play a role in worsened outcomes. Additional studies must be performed in order for the pathophysiologic mechanisms to be elucidated. GH has metabolic and growth-promoting effects in various tissues of humans. INTRODUCTIONAlthough hGH binds to hGHRs and hPRLRs, hPRL only binds to hPRLRs.