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Open access

Lei Lei, Yi-Hua Bai, Hong-Ying Jiang, Ting He, Meng Li, and Jia-Ping Wang

N6-methyladenosine (m6A) methylation has been reported to play a role in type 2 diabetes (T2D). However, the key component of m6A methylation has not been well explored in T2D. This study investigates the biological role and the underlying mechanism of m6A methylation genes in T2D. The Gene Expression Omnibus (GEO) database combined with the m6A methylation and transcriptome data of T2D patients were used to identify m6A methylation differentially expressed genes (mMDEGs). Ingenuity pathway analysis (IPA) was used to predict T2D-related differentially expressed genes (DEGs). Gene ontology (GO) term enrichment and the Kyoto Encyclopedia of Genes and Genomes (KEGG) were used to determine the biological functions of mMDEGs. Gene set enrichment analysis (GSEA) was performed to further confirm the functional enrichment of mMDEGs and determine candidate hub genes. The least absolute shrinkage and selection operator (LASSO) regression analysis was carried out to screen for the best predictors of T2D, and RT-PCR and Western blot were used to verify the expression of the predictors. A total of 194 overlapping mMDEGs were detected. GO, KEGG, and GSEA analysis showed that mMDEGs were enriched in T2D and insulin signaling pathways, where the insulin gene (INS), the type 2 membranal glycoprotein gene (MAFA), and hexokinase 2 (HK2) gene were found. The LASSO regression analysis of candidate hub genes showed that the INS gene could be invoked as a predictive hub gene for T2D. INS, MAFA,and HK2 genes participate in the T2D disease process, but INS can better predict the occurrence of T2D.

Open access

Ying Hua, Jinqiong Fang, Xiaocong Yao, and Zhongxin Zhu

Background

Obesity and osteoporosis are major public health issues globally. The prevalence of these two diseases prompts the need to better understand the relationship between them. Previous studies, however, have yielded controversial findings on this issue. Therefore, our aim in this study was to evaluate the independent association between waist circumference (WC), as a marker of obesity, and the bone mineral density (BMD) of the lumbar spine among middle-aged adults using data from the National Health and Nutrition Examination Survey (NHANES).

Methods

Our analysis was based on NHANES data from 2011 to 2018, including 5084 adults, 40–59 years of age. A weighted multiple linear regression analysis was used to evaluate the association between WC and lumbar BMD, with smooth curve fitting performed for non-linearities.

Results

After adjusting for BMI and other potential confounders, WC was negatively associated with lumbar BMD in men (β = −2.8, 95% CI: −4.0 to −1.6) and premenopausal women (β = −2.6, 95% CI: −4.1 to −1.1). On subgroup analysis stratified by BMI, this negative association was more significant in men with a BMI ≥30 kg/m2 (β = −4.1, 95% CI: −6.3 to −2.0) and in pre- and postmenopausal women with a BMI <25 kg/m2 (premenopausal women: β= −5.7, 95% CI: −9.4 to−2.0; postmenopausal women: β=−5.6, 95% CI: −9.7 to −1.6). We further identified an inverted U-shaped relationship among premenopausal women, with a point of inflection at WC of 80 cm.

Conclusions

Our study found an inverse relationship between WC and lumbar BMD in middle-aged men with BMI ≥30 kg/m2, and women with BMI <25 kg/m2.

Open access

Sidsel Mathiesen, Kaspar Sørensen, Marianne Ifversen, Casper P Hagen, Jørgen Holm Petersen, Anders Juul, and Klaus Müller

Objectives

Longitudinal assessment of testicular function after pediatric hematopoietic stem cell transplantation (HSCT) is needed to guide clinical follow-up. We investigated dynamics in male reproductive hormones after pediatric HSCT, focusing on pubertal timing and associations with testosterone deficiency and azoospermia in adulthood.

Methods

This retrospective, longitudinal study included 39 survivors median 19 years after pediatric HSCT. Serum concentrations of LH, testosterone, FSH, and inhibin B from the time of HSCT, during puberty, and into adulthood were analyzed. Pubertal timing (rise in LH and testosterone) was compared to a reference cohort of 112 healthy boys. Associations between reproductive hormone levels during puberty and adult testicular function (including semen quality) were investigated.

Results

Pubertal induction with testosterone was needed in 6/26 patients who were prepubertal at HSCT. In the remaining patients, pubertal timing was comparable to the reference cohort. However, 9/33 patients (without pubertal induction) developed testosterone deficiency in early adulthood, which was associated with higher LH levels from age 14 to 16 years. Azoospermia in adulthood was found in 18/26 patients without testosterone substitution. Higher FSH and lower inhibin B levels from mid-pubertal age were associated with azoospermia in adulthood, in patients being prepubertal at HSCT.

Conclusion

Our results indicate a substantial risk of deterioration in testicular function after pediatric HSCT, despite normal pubertal timing. Although reproductive hormone levels from mid-puberty indicated adult testicular function, prolonged follow-up into adulthood is needed in these patients, including clinical examination, reproductive hormone analysis, and semen sample for patients interested in their fertility potential.

Open access

Maki Igarashi, Tadayuki Ayabe, Kiwako Yamamoto-Hanada, Keiko Matsubara, Hatoko Sasaki, Mayako Saito-Abe, Miori Sato, Nathan Mise, Akihiko Ikegami, Masayuki Shimono, Reiko Suga, Shouichi Ohga, Masafumi Sanefuji, Masako Oda, Hiroshi Mitsubuchi, Takehiro Michikawa, Shin Yamazaki, Shoji Nakayama, Yukihiro Ohya, and Maki Fukami

Objective

Ultra-sensitive hormone assays have detected slight sex differences in blood estradiol (E2) levels in young children before adrenarche. However, the origin of circulating E2 in these individuals remains unknown. This study aimed to clarify how E2 is produced in young girls before adrenarche.

Design

This is a satellite project of the Japan Environment and Children’s Study organized by the National Institute for Environmental Studies.

Methods

We collected blood samples from healthy 6-year-old Japanese children (79 boys and 71 girls). Hormone measurements and data analysis were performed in the National Institute for Environmental Studies and the Medical Support Center of the Japan Environment and Children’s Study, respectively.

Results

E2 and follicle stimulating hormone (FSH) levels were significantly higher in girls than in boys, while dehydroepiandrosterone sulfate (DHEA-S) and testosterone levels were comparable between the two groups. Girls showed significantly higher E2/testosterone ratios than boys. In children of both sexes, a correlation was observed between E2 and testosterone levels and between testosterone and DHEA-S levels. Moreover, E2 levels were correlated with FSH levels only in girls.

Conclusions

The results indicate that in 6-year-old girls, circulating E2 is produced primarily in the ovary from adrenal steroids through FSH-induced aromatase upregulation. This study provides evidence that female-dominant E2 production starts several months or years before adrenarche. The biological significance of E2 biosynthesis in these young children needs to be clarified in future studies.

Open access

Xu Chen, Yi Tang, Shen Chen, Wenhua Ling, and Qing Wang

Background and aims

Non-alcoholic fatty liver disease (NAFLD) has become a common chronic liver disease in the world. Simple steatosis (SS) is the early phase of NAFLD. However, the molecular mechanisms underlying the development of steatosis have not yet been fully elucidated.

Methods

Two public datasets (GSE48452 and GSE89632) through the Gene Expression Omnibus (GEO) database were used to identify differentially expressed genes (DEGs) in the development of steatosis. A total of 72 participants including 38 normal histological controls and 34 SS patients were included in this study. Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and protein–protein interaction (PPI) network analysis were performed to explore the function of DEGs. The results were further confirmed in high-fat diet (HFD)-fed mice and oleate-treated HepG2 cells.

Results

Total 57 DEGs including 31 up- and 26 down-regulated genes between SS patients and healthy controls were determined. GO and KEGG analysis showed that most of the DEGs were enriched in the ligand–receptor signaling pathways. PPI network construction was used to identify the hub genes of the DEGs. MYC, ANXA2, GDF15, AGTR1, NAMPT, LEPR, IGFBP-2, IL1RN, MMP7, and APLNR were identified as hub genes, and IGFBP-2 expression was found to be reversely associated with hepatic steatosis, fasting insulin, HOMA-IR index, and ALT levels. In HFD-fed mice, hepatic IGFBP-2 was also downregulated and negatively associated with hepatic triglyceride (TG) levels. Moreover, overexpression of IGFBP-2 ameliorated the oleate induced accumulation of TGs in hepatocytes.

Conclusions

This study identified novel gene signatures in the hepatic steatosis and will provide new understanding and molecular clues of hepatic steatosis.

Open access

Sharon A Huish, Carl Jenkinson, Janet A Dunn, David J Meredith, Rosemary Bland, and Martin Hewison

Low serum 1,25-dihydroxyvitamin D (1,25(OH)2D) in end-stage renal disease (ESRD) is considered a consequence of elevated fibroblast growth factor 23 (FGF23) and concomitant reduced activity of renal 1α-hydroxylase (CYP27B1). Current ESRD treatment strategies to increase serum calcium and suppress secondary hyperparathyroidism involve supplementation with vitamin D analogues that circumvent 1α-hydroxylase. This overlooks the potential importance of 25-hydroxyvitamin D (25(OH)D) deficiency as a contributor to low serum 1,25(OH)2D. We investigated the effects of vitamin D (cholecalciferol) supplementation (40,000 IU for 12 weeks and maintenance dose of 20,000 IU fortnightly), on multiple serum vitamin D metabolites (25(OH)D, 1,25(OH)2D3 and 24,25(OH)2D3) in 55 haemodialysis patients. Baseline and 12 month data were compared using related-samples Wilcoxon signed rank test. All patients remained on active vitamin D analogues as part of routine ESRD care. 1,25(OH)2D3 levels were low at baseline (normal range: 60–120 pmol/L). Cholecalciferol supplementation normalised both serum 25(OH)D and 1,25(OH)2D3. Median serum 25(OH)D increased from 35.1 nmol/L (IQR: 23.0–47.5 nmol/L) to 119.9 nmol/L (IQR: 99.5–143.3 nmol/L) (P < 0.001). Median serum 1,25(OH)2D3 and 24,25(OH)2D3 increased from 48.3 pmol/L (IQR: 35.9–57.9 pmol/L) and 3.8 nmol/L (IQR: 2.3–6.0 nmol/L) to 96.2 pmol/L (IQR: 77.1–130.6 pmol/L) and 12.3 nmol/L (IQR: 9–16.4 nmol/L), respectively (P < 0.001). A non-significant reduction in daily active vitamin D analogue dose occurred, 0.94 µmcg at baseline to 0.77 µmcg at 12 months (P = 0.73). The ability to synthesise 1,25(OH)2D3 in ESRD is maintained but is substrate dependent, and serum 25(OH)D was a limiting factor at baseline. Therefore, 1,25(OH)2D3 deficiency in ESRD is partly a consequence of 25(OH)D deficiency, rather than solely due to reduced 1α-hydroxylase activity as suggested by current treatment strategies.

Open access

Xiaoxia Jia, Yaxin An, Yuechao Xu, Yuxian Yang, Chang Liu, Dong Zhao, and Jing Ke

Background

Obesity is known as a common risk factor for osteoporosis and type 2 diabetes mellitus (T2DM). Perirenal fat, surrounding the kidneys, has been reported to be unique in anatomy and biological functions. This study aimed to explore the relationship between perirenal fat and bone metabolism in patients with T2DM.

Methods

A total of 234 patients with T2DM were recruited from September 2019 to December 2019 in the cross-sectional study. The biochemical parameters and bone turnover markers (BTMs) were determined in all participants. Perirenal fat thickness (PrFT) was performed by ultrasounds via a duplex Doppler apparatus. Associations between PrFT and bone metabolism index were determined via correlation analysis and regression models.

Results

The PrFT was significantly correlated with β-C-terminal telopeptides of type I collagen (β-CTX) (r = −0.14, P < 0.036), parathyroid hormone (iPTH) (r = −0.18, P ≤ 0.006), and 25 hydroxyvitamin D (25-OH-D) (r = −0.14, P = 0.001). Multivariate analysis confirmed that the association of PrFT and β-CTX (β = −0.136, P = 0.042) was independent of other variables.

Conclusion

This study showed a negative and independent association between PrFT and β-CTX in subjects with T2DM, suggesting a possible role of PrFT in bone metabolism. Follow-up studies and further research are necessary to validate the associations and to elucidate the underlying mechanisms.

Open access

Khaled Kabarra, Pegah Golabi, and Zobair M Younossi

Nonalcoholic fatty liver disease (NAFLD) encompasses a spectrum of liver diseases ranging from simple fatty infiltration of liver parenchyma to the potentially progressive type of NAFLD called nonalcoholic steatohepatitis (NASH). Given the obesity epidemic, NAFLD and NASH have reached alarming levels globally. Recent data suggest that more than a quarter of the world population is affected by NAFLD; however, the disease prevalence is higher in certain patient population, that is, 55% prevalence rate among patients with type 2 diabetes (T2DM). Besides T2DM, NAFLD is also closely related to other metabolic abnormalities, such as visceral obesity, hypertension, and hyperlipidemia. It has been suggested that stage of liver fibrosis is the most important factor associated with mortality among patients with NAFLD. Additionally, patients with T2DM have increased risk of adverse outcomes. In addition to these metabolic abnormalities, older age and some genetic factors could pose additional risks. Patients with NAFLD and NASH have significantly impaired health-related quality of life than the general population. There is also a growing economical impact of NAFLD and NASH on healthcare systems around the globe. Despite a number of promising regimens as treatment options, healthy lifestyle modification with diet and exercise remains at the core of management of NAFLD and NASH.

Open access

Nannan Bian, Xiaomeng Sun, Biao Zhou, Lin Zhang, Qiu Wang, Yu An, Xiaohui Li, Yinhui Li, Jia Liu, Hua Meng, and Guang Wang

Objective

Bariatric surgery has become the most effective treatment for morbid obesity. Increasing evidence showed that bariatric surgery can alleviate insulin resistance and influence thyroid function. This study aimed to investigate the relationship between changes in thyroid function and adipose tissue insulin resistance (adipo-IR) after bariatric surgery.

Methods

A total of 287 non-diabetic participants with regular thyroid function were recruited and divided into the lean, overweight and obese groups. Among them, 50 morbidly obese patients submitted to bariatric surgery.

Results

The obese group had a higher level of adipo-IR, thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), FT3/free thyroxine (FT4) and metabolism disorders than the lean and overweight groups. BMI was correlated with TSH, FT3, FT3/FT4 and adipo-IR (r = 0.309, 0.315, 0.322 and 0.651, respectively, all P < 0.001). Adipo-IR was significantly correlated with TSH (r = 0.402, P < 0.001), FT3 (r = 0.309, P < 0.001), and FT3/FT4 (r = 0.228, P < 0.05). Bariatric surgery resulted in a sharp decline in BMI, adipo-IR, TSH, FT3 and FT3/FT4 levels, meanwhile, metabolic disorders improved. The decrease in BMI after bariatric surgery was significantly correlated with reductions in adipo-IR (r = 0.577, P < 0.001) and TSH (r = 0.401, P = 0.005). Interestingly, the fasting blood glucose, fasting insulin, adipo-IR and TSH in the higher TSH group decreased more remarkably than in the lower TSH group.

Conclusion

Obese individuals with higher TSH levels had an obvious metabolic improvement after bariatric surgery.

Open access

Marlena Mueller, Fahim Ebrahimi, Emanuel Christ, Christian Andreas Nebiker, Philipp Schuetz, Beat Mueller, and Alexander Kutz

Background

Primary hyperparathyroidism is a prevalent endocrinopathy for which surgery is the only curative option. Parathyroidectomy is primarily recommended in younger and symptomatic patients, while there are still concerns regarding surgical complications in older patients. We therefore assessed the association of age with surgical outcomes in patients undergoing parathyroidectomy in a large population in Switzerland.

Methods

Population-based cohort study of adult patients with primary hyperparathyroidism undergoing parathyroidectomy in Switzerland between 2012 and 2018. The cohort was divided into four age groups (<50 years, 50–64 years, 65–74 years, ≥75 years). The primary outcome was a composite of in-hospital postoperative complications. Secondary outcomes were intensive care unit (ICU) admission, unplanned 30-day-readmission, and prolonged length of hospital stay.

Results

We studied 2642 patients with a median (IQR) age of 62 (53–71) years. Overall, 111 patients had complications including surgical re-intervention, hypocalcemia, and vocal cord paresis. As compared to <50 year-old patients, older patients had no increased risk for in-hospital complications after surgery (50–64 years: odds ratio (OR): 0.51 (95% CI, 0.28 to 0.92); 65–74 years: OR: 0.72 (95% CI, 0.39 to 1.33); ≥75 years: OR: 1.03 (95% CI, 0.54 to 1.95), respectively. There was also no association of age and rates of ICU-admission and unplanned 30-day-readmission, but oldest patients had longer hospital stays (OR: 2.38 (95% CI, 1.57 to 3.60)).

Conclusion

≥50 year-old patients undergoing parathyroidectomy had comparable risk of in-hospital complications as compared with younger ones. These data support parathyroidectomy in even older patients with primary hyperparathyroidism as performed in clinical routine.