Association of genetic variants in GABRA3 gene and thyrotoxic hypokalaemic periodic paralysis in Thai population

Background Genetic predisposition has been suggested to play role in the pathogenesis of thyrotoxic hypokalaemic periodic paralysis (THPP). Objectives In this study, we assessed the differences of single‐nucleotide polymorphisms (SNP) allelic frequency between THPP patients and well‐characterized controls in order to find the susceptibility genetic variants related to THPP using microarray‐based assessments on pooled DNA. Methods Fifty cases of THPP and 50 male hyperthyroid patients without hypokalaemia as controls were recruited. Equal amounts of individual genomic DNA were pooled from each group. Estimated allele frequencies of SNPs were derived by averaging relative allele signal score obtained by Affymetrix GeneChip® Mapping 10K Arrays. Results Sixty‐nine loci that display robust allele frequency differences between THPP and controls were identified. SNP rs750841 (A > T) in intron 3 of the gamma‐aminobutyric acid (GABA) receptor α3 subunit (GABRA3) gene possessed the most significant difference in allele frequency (27% in THPP case and 5% in controls, P = 0·007). Actual allele frequencies obtained from genotyping in each individual were very similar to the estimated frequency from the pools (28% in THPP and 2% in controls, and P = 0·0002). Nearby DNA sequences of GABRA3 were sequenced and an additional two SNPs were found (A > C at exon 1 and G > T of rs12688128). Allele A of rs750841 and allele G of rs12688128 in intron 3 were predominantly found in THPP with significant genetic relative risk of 19 (P < 0·0002; 95%CI 2·4–151·6). Conclusions Whole‐genome scanning on pooled DNA provides an accurate, useful screening tool for elucidating genetic underpinnings of THPP. SNPs at intron 3 of GABRA3 are found to be associated with THPP.     

Acute hyperinsulinaemia and hyperlipidaemia modify circulating adiponectin and its oligomers

Objective Obesity and insulin resistance are associated with low adiponectin levels, although adiponectin is exclusively expressed in white adipose tissue. The mechanism beyond that paradox is not entirely clear, although insulin itself may reduce circulating adiponectin levels. However, obesity is also associated with hyperlipidaemia and the effects of free fatty acids (FFAs) and triglycerides (TG) on circulating adiponectin levels have not yet been investigated. Materials and methods We analysed the effect of an acute and euglycaemic elevation of insulin on adiponectin oligomers in 23 healthy individuals. In a subgroup including 11 healthy men, FFAs and TG were acutely elevated by infusion of heparin/lipids over 120 min. Again the effect on circulating adiponectin and its oligomers was investigated. Adiponectin was determined by ELISA, oligomers were detected by nondenaturating Western blot. Results Acute hyperinsulinaemia resulted in a significant reduction of total adiponectin to 7·74 ± 0·98 µg/ml (P = 0·004). High molecular weight (HMW) adiponectin did not change (0·80 ± 0·12 to 0·81 ± 0·14 µg/ml; P = 0·887), whereas MMW adiponectin decreased from 4·30 ± 0·51 to 3·78 ± 0·48 µg/ml (P = 0·005) and LMW adiponectin from 3·63 ± 0·42 to 3·15 ± 0·46 µg/ml (P = 0·048). Interestingly, heparin/lipid infusion also reduced circulating adiponectin levels (P = 0·001), which was primarily the result of reduced MMW adiponectin (P = 0·004), whereas LMW and HMW were not significantly affected. Conclusions The presented data suggest that both, hyperinsulinaemia and hyperlipidaemia, may contribute to low adiponectin levels in states of obesity.     

Effects of aromatase inhibition in hypogonadal older men: a randomized, double-blind, placebo-controlled trial

Objective To assess the effects of sustained aromatase inhibition in older hypogonadal men. Design and patients In a 1‐year randomized, double‐blind, placebo‐controlled trial, 88 men, aged 60 years and older with testosterone levels between 5·2 and 10·4 nmol/l on a single measure or between 10·4 and 12·1 nmol/l on two consecutive measures, and with symptoms of hypogonadism were recruited. Subjects received either anastrozole 1 mg daily or placebo. Measurements Changes in gonadal steroid hormone levels, body composition [by computerized tomography (CT) and dual X‐ray absorptiometry (DXA)], strength, prostate specific antigen (PSA), symptoms of benign prostatic hypertrophy (BPH), haematocrit and lipid levels were assessed. Results Testosterone levels increased from 11·2 ± 3·3 nmol/l at baseline to 18·2 ± 4·8 nmol/l at month 3 (P < 0·0001 vs. placebo) while bioavailable testosterone levels increased from 2·7 ± 0·8 nmol/l at baseline to 5·4 ± 1·7 nmol/l at month 3 (P < 0·0001 vs. placebo). Testosterone and biotestosterone levels peaked at month 3 and then declined by month 12 (though they remained significantly higher than baseline and greater than placebo). E₂ levels decreased from 55·8 ± 15·4 pmol/l at baseline to 42·2 ± 13·6 pmol/l at month 3 and then remained stable (P < 0·0001). Body composition and strength did not change, nor did PSA, BPH symptoms, haematocrit or lipid levels. Conclusions Anastrozole administration normalized androgen production in older hypogonadal men and decreased E₂ production modestly. These alterations did not improve body composition or strength.     

Substance P is increased in patients with sickle cell disease and associated with haemolysis and hydroxycarbamide use

Sickle cell disease (SCD) pain transitions from acute to chronic for unknown reasons. Chronic elevation of the pain neurotransmitter substance P (SP) sensitizes pain nociceptors. We evaluated SP levels in controls and SCD patients during baseline and acute pain and investigated associations between SP and age, gender, pain history, haemolysis and hydroxycarbamide (also termed hydroxyurea) use. Plasma SP levels were measured using enzyme‐linked immunosorbent assay. Independent samples t‐test compared SP levels between: (i) SCD baseline and controls, and (ii) SCD baseline and acute pain. Multivariate linear regression determined associations between SP and age, gender, pain history and hydroxycarbamide use. Spearman correlation determined an association between SP and haemolysis. We enrolled 35 African American controls, 25 SCD baseline and 12 SCD pain patients. SCD patients were 7‐19 years old. Mean ± standard deviation SP level (pg/ml) in SCD baseline was higher than controls (32·4 ± 11·6 vs. 22·9 ± 7·6, P = 0·0009). SP in SCD pain was higher than baseline (78·1 ± 43·4 vs. 32·4 ± 11·6, P = 0·004). Haemolysis correlated with increased SP: Hb (r = ?0·7, P = 0·0002), reticulocyte count (r = 0·61, P = 0·0016), bilirubin (r = 0·68, P = 0·0216), lactate dehydrogenase (r = 0·62, P = 0·0332), aspartate aminotransferase (r = 0·68, P = 0·003). Patients taking hydroxycarbamide had increased SP (β = 29·2, P = 0·007). SP could be a mediator of or marker for pain sensitization in SCD and a biomarker and/or target for novel pain treatment.     

Influence of ethnicity on IGF-I and procollagen III peptide (P-III-P) in elite athletes and its effect on the ability to detect GH abuse

Context A method based on the two GH dependent markers, IGF‐I and procollagen III peptide (P‐III‐P) has been proposed to detect exogenously administered GH. As previous studies involved predominantly white European elite athletes, it is necessary to validate the method in other ethnic groups. Objective To examine serum IGF‐I and P‐III‐P in elite athletes of different ethnicities within 2 h of competing at national or international events. Design Cross‐sectional observational study. Setting National and International sporting events. Subjects 1085 elite athletes of different ethnicities. Intervention Serum IGF‐I and P‐III‐P were measured and GH‐2000 discriminant function score was calculated. Effect of ethnicity was assessed. Results In men, IGF‐I was 21·7 ± 2·6% lower in Afro‐Caribbeans than white Europeans (P < 0·0001) but there were no differences between other ethnic groups. In women, IGF‐I was 14·2 ± 5·1% lower in Afro‐Caribbeans (P = 0·005) and 15·6 ± 7·0% higher in Orientals (P = 0·02) compared with white Europeans. P‐III‐P was 15·2 ± 3·5%, 26·6 ± 6·6% and 19·3 ± 5·8% lower in Afro‐Caribbean (P < 0·0001), Indo‐Asian (P < 0·0001) and Oriental men (P = 0·001), respectively, compared with white European men. In women, P‐III‐P was 15·7 ± 4·7% lower in Afro‐Caribbeans compared to white Europeans (P =0·0009) but there were no differences between other ethnicities. Despite these differences, most observations were below the upper 99% prediction limits derived from white European athletes. All GH‐2000 scores lay below the cut‐off limit proposed for doping. Conclusions The GH‐2000 detection method based on IGF‐I and P‐III‐P would be valid in all ethnic groups.     

Does partial surgical tumour removal influence the response to octreotide‐LAR in acromegalic patients previously resistant to the somatostatin analogue?

Objective To compare the intrapatient response to the same dose of slow‐release octreotide (OCT‐LAR) before and after noncurative surgery in acromegalic patients who did not attain disease control after primary treatment with OCT‐LAR. Design Prospective clinical study. Patients Eleven acromegalic patients (eight men, aged 42·45 ± 11·15 years, 10 macroadenomas) received OCT‐LAR (20 mg, n = 1; 30 mg, n = 10) every 28 days as the primary treatment (1stOCT‐LAR) for 11·3 ± 4·2 months, without IGF‐I normalization. They were subsequently submitted to surgery without cure and were then treated with the same dose of OCT‐LAR for 8·0 ± 6·5 months (2ndOCT‐LAR). Measurements GH and IGF‐I serum concentrations were obtained under basal conditions as well as during treatment. Pituitary tumour volume was assessed by magnetic resonance imaging (MRI) of the sella. IGF‐I was also expressed as a percentage of the upper limit of the normal age‐ and sex‐matched range (%ULNR IGF‐I). Results After 1stOCT‐LAR, there was a decrease in GH levels (P = 0·003) and %ULNR IGF‐I (P = 0·009) compared to baseline (B), but no IGF‐I normalization. Tumour shrinkage was observed in eight of 10 patients with macroadenomas (median 63·7%, range 24·5–75·5%). After surgery, mean levels of GH and %ULNR IGF‐I were lower than those at baseline (P = 0·0004 and P = 0·003, respectively), but not when compared to values during 1stOCT‐LAR (P = 1·000 and P = 0·957, respectively). MRI confirmed surgical tumour removal (median 64%, range 4·9–96·6%) in eight of the 10 patients. Comparing the 2ndOCT‐LAR results with postsurgical results, there were no significant decrease in %ULNR IGF‐I (P = 0·061) and GH levels (P = 0·414). Nine patients (82%) achieved IGF‐I normalization. The degree of surgical tumour reduction did not correlate with IGF‐I normalization (P = 0·794). When comparing the results between 1stOCT‐LAR and 2ndOCT‐LAR, there was a decrease, albeit not statistically significant, in serum GH levels (P = 0·059) and a significant decrease in %ULNR IGF‐I (P = 0·011). Conclusions Using strict criteria (same patient, same drug, same dose) our results strongly suggest that the surgical reduction of tumour mass can improve the outcome of OCT‐LAR treatment in acromegalic patients resistant to primary therapy with SA.     

Adiponectin, skeletal muscle adiponectin receptor expression and insulin resistance following dexamethasone

Objective Skeletal muscle is a major site of adiponectin action and of glucocorticoid‐induced insulin resistance. Little human data exist however, regarding the impact of exogenous glucocorticoids on adiponectin receptors in skeletal muscle. Design and patients Twelve subjects with type 2 diabetes and 12 controls underwent blood sampling and muscle biopsy of vastus lateralis before and after 4 days of 4 mg dexamethasone. Measurements (i) Total and high molecular weight (HMW) plasma adiponectin, glucose and insulin; (ii) Skeletal muscle adiponectin receptor AdipoR1 and AdipoR2 mRNA levels by quantitative real time RT‐PCR. Results Baseline total adiponectin (8·0 ± 0·89 vs. 12·5 ± 1·46 µg/ml, P = 0·013), HMW adiponectin (2·8 ± 0·44 vs. 5·9 ± 1·04 µg/ml, P = 0·014) and AdipoR2 mRNA levels (mean ΔC_T 14·71 ± 0·35 vs. 13·37 ± 0·28, P = 0·017) were significantly lower in diabetic subjects. After dexamethasone, AdipoR2 mRNA fell in the controls but there was no change in the diabetic group, while there was a significant increase in total (P = 0·002) and HMW adiponectin (P < 0·001) across both groups. Total and HMW plasma adiponectin correlated with clinical and biochemical measures of insulin sensitivity. However following dexamethasone which increased insulin resistance, the relationship between adiponectin and the biochemical measures was lost. Conclusions Plasma adiponectin and skeletal muscle AdipoR2 mRNA expression are reduced in subjects with diabetes; both are likely to contribute to the observed insulin resistance. Dexamethasone inhibits AdipoR2 mRNA expression in nondiabetic subjects, while there is a small rise in plasma adiponectin levels. The close relationship between plasma adiponectin and biochemical measures of insulin sensitivity is lost in the setting of glucocorticoid‐induced insulin resistance.     

Staged diabetes management according to individual patient insulin resistance and beta-cell function ameliorates glycaemic control in type 2 diabetes mellitus

Objective The current consensus algorithm for management of type 2 diabetes is based on the fasting glucose concentration and glycated haemoglobin A_1c (HbA_1c) level. We applied a new therapeutic strategy by assessing insulin secretion and insulin resistance, in addition to glucose concentrations in individual patients. Design and patients We enrolled 193 patients with type 2 diabetes. The patients were assigned to one of six groups according to insulin secretion measured by the serum fasting C‐peptide concentration and insulin resistance measured by an insulin tolerance test (ITT). The two groups were treated differently: 108 patients were treated using a new staged diabetes management (SDM) strategy and 85 patients continued with conventional therapy. Measurements We compared metabolic variables in the two groups at baseline and 12 months after enrolment. Results In patients treated with the SDM strategy, fasting glucose concentration decreased from 9·8 ± 2·1 to 8·2 ± 1·7 mmol/l (P < 0·001). Postprandial 2‐h glucose concentration decreased from 14·19 ± 3·34 to 12·27 ± 3·24 mmol/l (P < 0·001). HbA_1c level decreased from 8·37 ± 1·42% to 7·72 ± 1·39% (P < 0·001). About 43% of the new SDM group achieved an HbA_1c of < 7·0% compared with 25% of patients in the conventional treatment group. Conclusions The new SDM strategy, based on individual data on insulin resistance and insulin secretion, may provide valuable clinical benefits in non‐obese Korean patients with type 2 diabetes.     

GH and IGF-I deficiency are associated with reduced loss of fat mass after laparoscopic-adjustable silicone gastric banding

Context GH secretion is reduced in obese subjects and increases after body weight loss. It is still unclear if changes in the GH/IGF‐I axis after laparoscopic‐adjustable silicone gastric banding (LASGB) are associated with changes of body composition. Objective To analyse the relationships between changes in the GH/IGF‐I axis and those of body weight and composition before and after LASGB. Design Observational, prospective. Setting University ‘Federico II’ of Naples (Italy). Patients Seventy‐two severely obese females (BMI: 44·9 ± 4·68; mean age: 33·1 ± 11·34 years) were studied. Main outcome measures GH peak after GHRH plus arginine test, IGF‐I, IGFBP‐3 and ALS levels, fat mass (FM) and free fat mass (FFM) (by Bioelectrical Impedance Analysis) at baseline and 6 months after LASGB. The change in percentage of individual variables was calculated as well as that of excess of body weight loss (EBWL%). The FM%, FFM% and EBWL% were correlated with peak GH and IGF‐I levels changes. Results At baseline, GH deficiency (GHD) (GH peak = 4·1 µg/l) was found in 22 patients (31%), 16 of them also had IGF‐I deficiency (< –2SDS). IGF‐I levels were inversely correlated with waist circumference (r = –0·72, P < 0·001) and FM% (r = –0·75, P < 0·001). Post‐LASGB the patients were classified as follows: group (1) GH and IGF‐I sufficient (n = 44; 61·1%); group (2) GH and IGF‐I deficient (n = 14; 19·4%) and group (3) GH sufficient and IGF‐I deficient (n = 14; 19·4%). The percentage changes of EWBL (P < 0·05, P = 0·051, respectively) and FM (P < 0·001, P < 0·01, respectively) were lower in groups (2) and (3) than in group (1). At the stepwise linear regression analysis, postoperative IGF‐I levels were the strongest determinant of percent changes of FM (P < 0·0001), of FFM (P = 0·009) and of EBWL (P < 0·0001). Conclusions IGF‐I levels is the most sensitive to unfavourable changes in body composition 6 months after LASGB making investigation of the somatotropic axis useful in the evaluation of bariatric surgery outcomes.     

Epitope recognition patterns of thyroid peroxidase autoantibodies in healthy individuals and patients with Hashimoto's thyroiditis*

Objective Thyroid peroxidase antibodies (TPOAb) are markers of autoimmune thyroid disease (AITD), including Hashimoto's thyroiditis (HT), but naturally occurring TPOAb are also detectable in healthy, euthyroid individuals. In AITD, circulating TPOAb react mainly with two immunodominant regions (IDR), IDR‐A and IDR‐B. The present study was undertaken in order to compare the epitope recognition pattern of TPOAb in HT patients and healthy subjects. Design Sera from 21 out of 98 healthy controls were selected on the basis of high TPOAb values, required for determination of TPOAb recognition pattern; as were sera from 92 HT patients. Measurements Measurement of IDR‐reactivity was possible in 90 patients and 12 controls. IDR‐A‐, IDR‐B‐ and non‐IDR‐A/non‐IDR‐B‐Ab constituted 24 ± 11%, 50 ± 15% and 26 ± 12%, respectively, in the patients. The distribution in the controls was distinctly different, only 12 ± 13% being directed against IDR‐A (P < 0·002) and 66 ± 22% against IDR‐B (P < 0·002). Half of the healthy individuals, vs. none of the HT patients, lacked IDR‐A reactivity completely (P < 0·0001). In HT patients, IDR‐B‐Ab proportions increased slightly with increasing TPOAb levels (P < 0·05), while IDR‐B‐Ab of the controls showed a strong opposite trend (P < 0·0001). Accordingly, the proportion of non‐A/non‐B‐Ab correlated with TPOAb levels in the healthy controls (P < 0·008), and an inverse correlation was seen in HT patients (P < 0·02). Conclusion The data suggest that TPOAb do not differ only in quantity between HT patients and healthy individuals, but may also follow distinct qualitative patterns. Larger studies are required to confirm this, and to determine whether the propensity to produce antibodies to certain TPO epitopes, for example, IDR‐A, is of pathogenic relevance.     

Metformin maintains the weight loss and metabolic benefits following rimonabant treatment in obese women with polycystic ovary syndrome (PCOS)

Objective Rimonabant has been shown to reduce weight, free androgen index (FAI) and insulin resistance in obese patients with polycystic ovary syndrome (PCOS) compared to metformin. Studies have shown that significant weight regain occurs following the cessation of rimonabant therapy. This study was undertaken to determine if subsequent metformin treatment after rimonabant would maintain the improvement in weight, insulin resistance and hyperandrogenaemia in PCOS. Design An extension study for 3 months with the addition of metformin to the randomised open labelled parallel study of metformin and rimonabant in 20 patients with PCOS with a body mass index ≥ 30 kg/m². Patients who were on 3 months of rimonabant were changed over to metformin for 3 months, whereas those on 3 months of metformin were continued on metformin for another 3 months. Measurements The primary end‐point was a change in weight; secondary end‐points were a change in FAI and insulin resistance. Results The mean weight loss of 6·2 kg associated with 3 months of rimonabant treatment was maintained by 3 months of metformin treatment (mean change +0·2 kg, P = 0·96). Therefore, the percentage reduction in weight remained significantly higher in the rimonabant/metformin group compared to metformin only subjects at 6 months compared to baseline (–6·0 ± 0·1%vs. –2·8 ± 0·1%, P = 0·04). The percentage change in testosterone and FAI from baseline to 6 months was also greater in the rimonabant/metformin group. [Testosterone (–45·0 ± 5·0%vs. –16 ± 2·0%, P = 0·02); FAI (–53·0 ± 5·0%vs. –17·0 ± 12·2%, P = 0·02)]. HOMA‐IR continued to fall significantly in the rimonabant/metformin group between 0, 3 and 6 months (4·4 ± 0·5 vs. 3·4 ± 0·4 vs. 2·7 ± 0·3, respectively, P < 0·01) but not at all in the metformin only group (3·4 ± 0·7 vs. 3·4 ± 0·8 vs. 3·7 ± 0·8, respectively, P = 0·80). Total cholesterol and LDL reduced significantly in both groups, but improvements in triglycerides and HDL were limited to the rimonabant/metformin group. Conclusions In these obese patients with PCOS, metformin maintained the weight loss and enhanced the metabolic and biochemical parameters achieved by treatment with rimonabant, compared to 6 months of metformin treatment alone.     

Perioperative plasma active and total ghrelin levels are reduced in acromegaly when compared with in nonfunctioning pituitary tumours even after normalization of serum GH

Objective Ghrelin is a novel gastric peptide known to stimulate GH secretion, but the relationship between ghrelin and the GH‐insulin‐like growth factor (IGF)‐1 axis in GH excess or deficiency is poorly understood. This study investigated dysregulation of ghrelin secretion in acromegaly and its short‐term postoperative recovery. Methods A prospective study was conducted on eight patients who underwent complete transsphenoidal resection of GH‐producing pituitary adenomas (acromegaly group) and 22 for endocrinologically nonfunctioning pituitary tumours (control group). Active and total plasma ghrelin levels were measured serially before and after surgery. Results Preoperative active and total plasma ghrelin concentrations (mean ± SD; fmol/ml) were significantly reduced in acromegalic patients when compared with those in the controls (9·6 ± 4·3 and 157·4 ± 65·6 vs. 21·8 ± 13·0 and 267·1 ± 111·4; P = 0·023 and P = 0·021, respectively). Both levels were still significantly suppressed on postoperative Day 7 in the acromegaly group when compared with those in the control group (11·7 ± 4·3 and 197·8 ± 68·9 vs. 22·5 ± 12·6 and 302·7 ± 100·0; P = 0·038 and P = 0·018, respectively). The ratios of active to total ghrelin were not significantly different between the two groups before and after operation. In acromegalic patients, active and total ghrelin levels remained significantly suppressed even after normalization of serum GH levels. Conclusions The putative negative feedback mechanism of GH on ghrelin secretion may in part account for the low ghrelin levels observed in acromegalic patients, and the mechanism may persist even after normalization of serum GH.     

Resistin gene variation is associated with systemic inflammation but not plasma adipokine levels, metabolic syndrome or coronary atherosclerosis in nondiabetic Caucasians

Objective Resistin causes insulin resistance and diabetes in mice whereas in humans it is linked to inflammation and atherosclerosis. Few human genetic studies of resistin in inflammation and atherosclerosis have been performed. We hypothesized that the –420C>G putative gain‐of‐function resistin variant would be associated with inflammatory markers and atherosclerosis but not with metabolic syndrome or adipokines in humans. Design and methods We examined the association of three resistin polymorphisms, –852A>G, –420C>G and +157C>T, and related haplotypes with plasma resistin, cytokines, C‐reactive protein (CRP), adipokines, plasma lipoproteins, metabolic syndrome and coronary artery calcification (CAC) in nondiabetic Caucasians (n = 851). Results Resistin levels were higher, dose‐dependently, with the –420G allele (CC 5·9 ± 2·7 ng/ml, GC 6·5 ± 4·0 ng/ml and GG 7·2 ± 4·8 ng/ml, trend P = 0·04) after age and gender adjustment [fold higher for GC + GG vs. CC; 1·07 (1·00–1·15), P < 0·05)]. The –852A>G single nucleotide polymorphism (SNP) was associated with higher soluble tumour necrosis factor‐receptor 2 (sol‐TNFR2) levels in fully adjusted models [1·06 (95% CI 1·01–1·11), P = 0·01)]. The estimated resistin haplotype (GGT) was associated with sol‐TNFR2 (P = 0·04) and the AGT haplotype was related to CRP (P = 0·04) in the fully adjusted models. Resistin SNPs and haplotypes were not associated with body mass index (BMI), fasting glucose, insulin resistance, metabolic syndrome, adipokines or CAC scores. Conclusions Despite modest associations with plasma resistin and inflammatory biomarkers, resistin 5′ variants were not associated with metabolic parameters or coronary calcification. This suggests that resistin is an inflammatory cytokine in humans but has little influence on adiposity, metabolic syndrome or atherosclerosis.     

Bone mineral density and bone turnover in Romanian children and young adults with classical 21-hydroxylase deficiency are influenced by glucocorticoid replacement therapy

Objective It remains controversial if glucocorticoid replacement therapy impairs bone mineral density (BMD) in young patients with 21‐hydroxylase deficiency. We aimed to analyze the impact of treatment variables, phenotype and genotype on BMD and bone metabolism in these patients. Design Cross‐sectional study. Measurements Twenty‐eight Caucasian patients with classical 21‐hydroxylase deficiency (5–39 years). Clinical parameters, hormonal status, osteocalcin (OC), C‐terminal telopeptide of type I collagen (CTX), genotype and lumbar BMD (Z‐scores) were assessed. Cumulative and mean hydrocortisone equivalent doses were calculated for the entire treatment period. Results Patients with severely reduced BMD Z‐scores (≤–2·5 SD) had significantly higher mean/cumulative glucocorticoid doses compared to patients with moderately reduced (P = 0·003/P = 0·026) and normal Z‐scores (> –1 SD) (P = 0·005/P = 0·011). Mean hydrocortisone equivalent doses > 20 mg/m²/day led to significantly lower lumbar BMD Z‐scores (–2·16 ± 1·4 SD) vs. doses ≤ 20 mg/m²/day (–0·59 ± 1·25 SD) (P = 0·008). BMD correlated negatively with mean/cumulative glucocorticoid doses and treatment duration. OC (86·45 ± 37·45 ng/ml) and CTX (1·45 ± 0·43 ng/ml) were significantly increased compared to an age‐ and sex‐matched control group in patients with active growth; only CTX was slightly increased in patients who completed growth. Conclusions High cumulative and mean glucocorticoid doses negatively impact on BMD in children and young adults with classical 21‐hydroxylase deficiency. Substitution therapy should be adapted particularly at this life period to prevent bone loss.     

Lipid-lowering therapy does not affect the postprandial drop in high density lipoprotein-cholesterol (HDL-c) plasma levels in obese men with metabolic syndrome: a randomized double blind crossover trial

Introduction The postprandial lipid metabolism in metabolic syndrome patients is disturbed and may add to the increased cardiovascular risk in these patients. It is not known whether postprandial high density lipoprotein‐cholesterol (HDL‐c) metabolism is also affected and whether this can be influenced by statin and/or ezetimibe treatment. Methods Prospective, randomized, double blind, crossover trial comparing simvastatin 80 mg with simvastatin/ezetimibe 10 mg/10 mg treatment for 6 weeks on postprandial HDL‐c metabolism in 15, nonsmoking, male, obese metabolic syndrome patients (Adult Treatment Panel III, ATPIII). Only study medication was allowed. HDL‐c concentrations, cholesteryl ester transfer (CET), CET protein (CETP) mass and adiponectin were measured before and after oral fat loading. ClinicalTrials.gov NCT00189085. Results Plasma HDL‐c levels remained stable during continuous fasting following an overnight fast. Pre‐fat load HDL‐c concentrations without treatment, after simvastatin and simvastatin/ezetimibe treatment were 1·15 ± 0·04, 1·16 ± 0·05 and 1·11 ± 0·04 mmol/l. Fat load induced a 11% drop in HDL‐c plasma levels; 1·02 ± 0·05 mmol/l (P < 0·001) which was not affected by either therapy. Triglyceride levels during fat load were similar after both treatments. Total CET increased from 9·73 ± 0·70 to 12·20 ± 0·67 nmol/ml/h (P = 0·004). Four hours after fat loading CETP mass was increased while adiponectin levels were decreased, irrespective of treatment. Discussion HDL‐c levels decrease as CET increases after fat loading in obese metabolic syndrome patients. This is not influenced by either simvastatin or simvastatin/ezetimibe treatment. After fat loading, CETP mass and CET increased, and adiponectin decreased pointing towards a potential role for intra‐abdominal fat. Decreased postprandial HDL‐c levels may contribute to the increased cardiovascular risk in metabolic syndrome patients on top of already low HDL‐c levels.     

Relation between plasma fibroblast growth factor-23, serum fetuin-A levels and coronary artery calcification evaluated by multislice computed tomography in patients with normal kidney function

Objective To examine the correlation of plasma fibroblast growth factor (FGF)‐23 and serum fetuin A levels with the coronary artery calcification score (CACS) in patients with normal kidney function. Background Vascular calcification is an active process that may be aggravated by hyperphosphataemia and hypercalcaemia. FGF‐23 and human fetuin‐A have been associated with calcifying arteriosclerosis in renal failure. Plasma FGF‐23 was identified as an independent factor negatively associated with peripheral vascular calcification. Fetuin‐A acts as a systemic inhibitor of ectopic calcification in dialysis patients and can be correlated to the survival of these patients. Very few data exists on the role of FGF‐23 and fetuin‐A in coronary calcification of patients without impaired kidney function. Materials and methods Sixty‐four patients, 21 females and 43 males, were subjected to 64‐slice coronary computed tomography (CT) to evaluate coronary artery calcification (CAC). Plasma intact FGF‐23 was determined by ELISA. Serum fetuin‐A concentration were evaluated nephelometrically. Results Mean plasma FGF‐23 level was 20·4 ± 9·1 pg/ml and serum fetuin‐A was 0·46 ± 0·09 g/l. There was no correlation between FGF‐23 (P = 0·777) and fetuin‐A (P = 0·767) levels and the CACS. No correlation was found between the presence of noncalcified plaques and coronary artery stenosis (CAS) ≥  50%, and FGF‐23 (P = 0·313 and P = 0·775) and fetuin‐A levels (P = 0·601 and P = 0·659). Conclusion Plasma intact FGF‐23 and serum fetuin‐A concentration do not correlate with the CACS, the grade of stenosis or presence of noncalcified plaques of the coronary arteries in patients with normal kidney function.     

Serum resistin is positively correlated with the accumulation of metabolic syndrome factors in type 2 diabetes

Objective Resistin, secreted from adipocytes, causes insulin resistance in rodents. We reported that the G/G genotype of a resistin gene promoter single nucleotide polymorphism (SNP) at ?420 increases type 2 diabetes (T2DM) susceptibility by enhancing promoter activity. We also showed that serum resistin was positively correlated with G at SNP‐420, the duration of T2DM, and HbA1c in T2DM. The aim of this study was to determine the relation between serum resistin and factors related to the metabolic syndrome (MetS) in T2DM. Design, patients and measurements We analysed 238 Japanese T2DM subjects (124 males and 114 females, age 60·2 ± 11·3 years, body mass index (BMI) 24·1 ± 3·9) whose overnight fasting sera were available. Serum resistin was measured using ELISA. Results Serum resistin was higher in subjects with either obesity (P = 0·041), low HDL (P = 0·004), high triglycerides (TG) (P = 0·019), hypertension (HT) (P = 0·001) or atherosclerosis (P = 0·012). Simple regression analysis revealed that serum resistin was correlated with lower HDL, TG and high‐sensitivity C‐reactive protein (hsCRP). Multiple regression analysis (or logistic regression analysis for HT), adjusted for age, gender, BMI and the duration of T2DM, revealed that serum resistin was correlated with lower HDL (P = 0·008), TG (P = 0·041), HT (P = 0·031) and hsCRP (P = 0·004). Serum resistin was positively correlated with the number of MetS factors, independent of age, gender and the duration of T2DM (P < 0·001). Adjustment by either thiazolidinedione (TZD) treatment or hsCRP had no effects on these findings. Conclusions Serum resistin was positively correlated with the accumulation of MetS factors in T2DM.     

Macroprolactin does not contribute to elevated levels of prolactin in patients on renal replacement therapy

Objective Three molecular forms of PRL with molecular weights of 23, 50–60 and > 100 kDa have been defined. The high‐molecular‐weight forms are called macroprolactin. Different immunoassays produce varyingly elevated results with macroprolactin‐containing sera. The kidneys are reported to clear 25% of PRL from the circulation. Hyperprolactinaemia is seen in 20–75% of patients with chronic renal failure (CRF). PRL clearance rate has been reported to be reduced in CRF and the resulting hyperprolactinaemia is due to reduced renal function. Patients To determine the contribution of macroprolactinaemia to elevated PRL levels in CRF, 91 patients receiving haemodialysis (HD), continuous ambulatory peritoneal dialysis (CAPD) and renal transplantation (RT) therapies and 72 control subjects were included in the study. Measurements Serum PRL levels were measured by a sandwich immunoassay with electrochemical detection. Following polyethylene glycol (PEG) precipitation, recovery ratios were calculated and samples with a recovery of < 50% were identified as having macroprolactin isoforms. Results The serum and supernatant PRL levels of CRF patients were significantly higher than those of the control group (P < 0·001). The serum PRL levels of HD and CAPD patients were significantly higher than those of the RT patients (P < 0·001). The serum PRL levels of the RT patients and the control group did not differ significantly (P > 0·05). A moderate correlation was found between PRL and creatinine levels (r = 0·609, P < 0·001). Conclusions The hyperprolactinaemia seen in renal replacement therapy is not associated with the presence of macroprolactin isoforms but with the decline in renal function.     

Insulin resistance and body composition in preterm born children during prepubertal ages

Background Premature born children may show insulin resistance in childhood which may be due to intrauterine or postnatal adverse environmental factors. Objective Aim of this study was to evaluate insulin resistance and body composition in preterm born children born appropriate for gestational age (AGA) or small for gestational age (SGA) and relations with IGF‐I, IGFBP‐3 axis. Methods Ninety‐three preterm born children grouped as premature SGA (n = 30) and premature AGA (n = 63) were evaluated at age 4·6 ± 0·2 years and 4·7 ± 0·1 years with respect to their glucose, insulin, IGF‐I, IGFBP‐3, IGFBP‐1, leptin levels and body composition by dual‐energy X‐ray absorptiometry. Their data were compared to that of body mass index (BMI) matched term SGA (n = 42) and term AGA (n = 44) children of age 4·5 ± 0·2 and 3·8 ± 0·1 years. All children had height appropriate for their target height. Insulin resistance was evaluated by basal insulin and homeostasis model assessment for insulin resistance (HOMA‐IR). Results Basal insulin level was similar in preterm AGA (4·3 ± 1·4 pmol/l) and term AGA (7·9 ± 6·4 pmol/l) children at similar and normal BMI levels. Preterm SGA children had insulin levels (5·0 ± 3·6 pmol/l) similar to preterm AGA children but significantly lower than that in term SGA children (23·7 ± 20·8 pmol/l) (P = 0·001). Similar results were obtained for HOMA‐IR. Term SGA children had also significantly lower IGFBP‐1 levels. Body composition, leptin and IGFBP‐3 did not differ between the respective groups. IGF‐I was lower in preterm AGA (5·0 ± 0·6 nmol/l) than in term AGA (8·3 ± 1·2 nmol/l) (P < 0·001) children. Conclusions Premature born AGA and SGA children do not have insulin resistance when compared to term children if they have made a catch‐up growth appropriate for their target height and have normal BMI. The similar insulin levels in preterm SGA and preterm AGA children together with increased insulin levels in term SGA children points to the fact that it is the intrauterine restriction in the third trimester that has an adverse effect on future adverse metabolic outcome.