Prevalence and characteristics of MAFLD in Chinese adults aged 40 years or older:A community-based study

Background: Nonalcoholic fatty liver disease(NAFLD) was recently proposed to be renamed metabolic dysfunction-associated fatty liver disease(MAFLD) with the diagnostic criteria revised. We investigated the similarities and differences in the prevalence and clinical characteristics of MAFLD and NAFLD in Chinese adults. Methods: A cross-sectional study of 9980 Chinese individuals aged 40 years or older was performed between 2011 and 2012 using randomized, stratifed cluster sampling in Shanghai, China. A detailed questionnaire and the results of abdominal ultrasonography, a standardized 2-h 75-g oral glucose tolerance test and blood biochemical examinations were collected. Results: A total of 9927 subjects were included in this study. The prevalence of MAFLD(40.3%) was significantly higher than that of NAFLD(36.9%)( P < 0.05). MAFLD was highly prevalent in type 2 diabetes mellitus(T2DM)(53.8%), impaired fasting glucose(35.7%) and impaired glucose tolerance(40.9%). High risk of advanced fbrosis based on fbrosis-4 was highly prevalent(14.7%) in lean MAFLD with T2DM. Among 9927 subjects, 3481(35.1%) fulflled the diagnostic criteria for MAFLD and NAFLD(MAFLD + NAFLD +), 521(5.2%) MAFLD + NAFLD-, and 181(1.8%) MAFLD-NAFLD +. The MAFLD + NAFLD-group had more signifcant metabolic disorders than those in the MAFLD + NAFLD + group(all P < 0.05). Among MAFLD-NAFLD + subjects, 82.9% had metabolic disorders. Conclusions: The new defnition of MAFLD may better reflect the pathogenesis related to metabolism. Future research should focus on studying the natural history, pathogenesis and treatment effectivity of the overlap and non-overlap of NAFLD and MAFLD subjects.

DIFFERENTIAL EXPRESSION OF GENES IN OMENTAL FAT OF NORMAL WEIGHT AND OBESE SUBJECTS AND OBESE DIABETIC PATIENTS USING cDNA MICROARRAY

Objective To identify genes differentially expressed in omental fat of normal weight subjects, obese subjects and obese diabetic patients. Methods Using a high-density cDNA microarray, gene expression profile of omental fat from normal weigh subjects, obese subjects and obese diabetic patients were compared. Results Totally, 119 and 257 genes were up-regulated in obese subjects and obese diabetic patients respectively, while 46 and 58 genes were down-regulated. A total of 77 genes, including PDK4, which switched from carbohydrate to fatty acids as the primary source of fuel, were up-regulated in both obese and obese diabetic patients, while 8 genes, including key enzymes in lipid synthesis, such as HMG-CoA synthase, fatty acid synthase and stearoyl-CoA desaturase, were down-regulated in both groups. Tyrosine-3-monooxygenase/tryptophan 5-monooxygenase activation protein θ (YWHAZ), a negative regulator for insulin signal transduction, was up-regulated only in obese diabetic patient, but not in normal-glycemic obese subjects. Conclusion The study demonstrated that decrease of lipogenesis along with increase of fatty acids oxidation of adipose tissue could be a common cause of insulin resistance in obesity and type 2 diabetes, while block of insulin signal transduction may trigger the transition from obesity to diabetes. Further exploration of these genes will be useful in the understanding of the pathogenesis of obesity and diabetes.

RELATIONSHIP OF SERUM ADIPONECTIN LEVELS WITH ADIPOSITY, GLUCOCORTICOIDS,LEPTIN AND INSULIN

Objective To investigate the relationship between serum adiponectin levels with adiposity,glucocorticoids, insulin and leptin in Cushing’ s syndrome, obesity and non-obese subjects. Methods The serumadiponectin concentrations were measured in 104 non-obese and 57 overweight or obese subjects byRIA. 15 patients with Cushing’ s syndrome, 10 with obesity and 9 non-obese subjects were investigated, with theirserum adiponectin, glucocorticoids, insulin and leptin levels measured at 8:00, 12:00, 16:00, 20:00, 24:00 and3:00. Dexamethasone suppression tests in both obesity and Cushing’s syndrome were performed at the dose of Img,2mg and 5mg. Results The serum adiponectin concentrations in non-obese were (10. 15 ±6. 33)mg/L in maleand (13. 82 ±6. 09)mg/L in female, and those in overweight or obese ones were (5. 78 ±3. 55)mg/L in male and(8. 13 ± 4. 32) mg/L in female. In both men and women, the fasting adiponectin levels in overweight or obese sub-jects were lower than those of the non-obese ones, and serum adiponectin concentrations were significantly nagetivelycorrelated with BMI, % Fat and waist circumference. The circadian rhythmicity of adiponectin was not distinct, butthe adiponectin levels in obesity were lower than those of the non-obese subjects at all 6 time spots. The serum adi-ponectin area under curve (AUC) were significantly nagetively correlated with BMI, waist circumference and insulinA UC. The adiponectin levels with dexamethasone administration for a short-term both at higher doses and lower do-ses did not change, but was decreased after surgery. Conclusion Adiponectin is a hormone secreted by adipo-cytes which may intimately related to obese and insulin resistance. Therefore, any treatment that could be used to in-crease adiponectin should be beneficial. Neither long-term endogenous hyper-glucocorticoid nor short-term dexam-ethasone administration may affect the adiponectin levels, and similarly, no change with elevated postprandial insu-lin levels.

STUDY ON OBESITY RELATED FACTORS: FFA, LEPTIN AND ADIPONECTIN IN SUBJECTS WITH VARYING GLUCOSE TOLERANCE

Objective To study the fasting serum levels of obesity related factors: FFA, leptin and adi-ponectin in subjects with varying glucose tolerance and their relationship with BMI, insulin sensitivity index and isletbeta-cell function. Methods Serum levels of FFA, leptin and adiponectin in 24 normal, 32 simple obese, 34IGT and 36 T2DM subjects were measured by ACS-ACOD assay or RIA. Results The serum levels of leptin andFFA in three groups:simple obese, IGT and DM were much higher than those in normal control (P <0. 001). Incontrast, serum level of adiponectin of simple obese, IGT and DM groups were significant lower than that of normalcontrol, among them DM subjects had the lowest level (P <0. 001). Correlation analysis showed that FFA was pos-itively correlated to BMI, WHR, FBG, fasting insulin level and negatively correlated to SI; adiponectin was negativelycorrelated to BMI, WHR, FBG, PBG, but positively correlated to SI and AIRg; and leptin was positively correlated toBMI, fasting insulin and AIRg when negatively correlated to FBG and SI. None of them was correlated to age.Conclusion Subjects with insulin resistance have high serum FFA and leptin levels but low serum adiponectin level.With the glucose tolerance deterioration, serum FFA level increases much higher while the adiponectin deceases muchlower. Unlike insulin, none of these obesity related factors can be used as the simple indicating or determining factorof SI, though each of them, to different extent, takes part in the development of insulin resistance.

A 2-way cross-over,open-labeled trial to compare efficacy and safety of insulin Aspart and Novolin R delivered with CSII in 21 Chinese diabetic patients

Background Subcutaneous absorption is accelerated by the monomeric conformation of insulin Aspart, which provides good glycemic control with a lower risk of hypoglycemia and less body weight increase. In the present study we investigated the efficacy and safety of a rapid-acting human insulin analogue （insulin Aspart） delivered with continuous subcutaneous insulin infusion （CSII） into Chinese diabetic patients. Methods A total of 21 patients with type 1 or type 2 diabetes were recruited for the 2-way cross-over, open-labeled trial, and then randomized to Group A （n=-10, treated with insulin Aspart） or Group B （n=11, treated with Novolin R）. Insulin Aspart and Novolin R were administered by CSII. Capillary glucose concentrations were measured at 8 time points, pre-prandial and postprandial, bedtime （10 pm）, midnight （2 am） every day during the treatment. Results The average capillary glucose profiles for the day were much better controlled in Group A than in Group B （P〈0.01）. The blood glucose levels were particularly better controlled in Group A than in Group B at pre-breakfast （（6.72±1.24） mmol/L vs （7.84±1.58） mmol/L, P=0.014）, post-breakfast （（8.96±2.41） mmol/L vs （11.70±3.11） mmol/L, P=0.0028）, post-supper （（8.15±2.10） mmol/L vs （10.07±2.36） mmol/L, P=0.008）, bed time （（7.73±1.72） mmol/L vs （9.39±.2.05） mmol/L, P=0.007） and midnight （（6.32±1.16） mmol/L vs （7.48±1.36） mmol/L, P=0.0049）. There was no significant difference in the frequency of hypoglycemic episodes between the two groups. Conclusion Insulin Aspart results in better control of blood glucose levels than regular human insulin （Novolin R） in diabetic patients during delivery by CSII.

Role and mechanism of rosiglitazone on the impairment of insulin secretion induced by free fatty acids on isolated rat islets

Background Prolonged exposure of pancreatic β-cells to fatty acids increases basal insulin secretion but inhibits glucose-stimulated insulin secretion. Rosiglitazone is a new antidiabetic agent of the thiazolidinediones. However, the relationship between thiazolidinediones and insulin secretion is highly controversial. The aim of this study is to explore the effect and mechanism of rosiglitazone on insulin secretion of islets under chronic exposure to free fatty acids （FFA）.Methods Pancreatic islets were isolated from the pancreata of male Sprague-Dawley rats by the collagenase digestion and by the dextran gradient centrifugation method. The purified islets were cultured in the presence or absence of rosiglitazone and palmitate for 48 hours. The insulin secretion was measured by radioimmunoassay. The mRNA level of peroxisome proliferator-activated receptor y, uncoupling protein 2 0dCP-2） and insulin were determined by real-time polymerase chain reaction （PCR）. The cell cytotoxicity assay was measured by cell counting kit-8.Results Islets exposed to elevated palmitate for 48 hours showed an increased basal and a decreased glucose-stimulated insulin secretion （P〈0.01）. The mRNA level of UCP-2 was increased by 3.7 fold in the 0.5 mmol/L concentration of palmitate. When islets were cultured with palmitate （0.5 mmol/L） in the presence of rosiglitazone （1.0 pmol/L）, both basal and glucose-stimulated insulin secretion reversed to a pattern of control islets （P〈0.05, P〈0.0 1）. The addition of rosiglitazone in the culture medium decreased the mRNA level of UCP-2 by 2.2 fold, having a statistically significant difference （P〈0.05） as compared with islets cultured with palmitate alone. The cell viability was not affected.Conclusion The protective effects of rosiglitazone on insulin secretion of isolated pancreatic islets under chronic exposure to palmitate might be mediated through the downregulation of UCP-2 expression.

The localization of type 2 diabetes susceptibility gene loci in northern Chinese Han families

We conducted a genome-wide scan, in which 358 well distributed fluorescent dye-labeled microsatellite marker sets were applied in 32 Chinese Han type 2 diabetes families from Northern China to search for the susceptibility gene loci. The data collected from screening all the chromosomes of genome were genotyped by using genescan and genotyping software, then, parametric and non-parametric multipoint test, and affected sib-pair analysis as well, were used to analyze the data. We identified some susceptibility gene loci residing in chromosomes 1,12,18,20, respectively, or precisely, located around D1S214, D1S207, D1S218, D1S235, D12S336, D18S61 and D20S118. The comparison of this result with those from other regions and races reflected the complexity and heterogeneity of type 2 diabetes.

A novel missense mutation, GGC（Arg454） → TGC（Cys）, of CYP11B1 gene identified in a Chinese family with steroid 11β-hydroxylase deficiency

Background Steroid 11β-hydroxylase deficiency （11β-OHD）, an autosomal recessive inherited disease, accounts for 5%-8% of congenital adrenal hyperplasia. It was scarcely reported in China. This article reports two Chinese girls with 11β-OHD. Methods The two patients were sisters and presented with hypertrichosis, skin pigmentation, laryngeal prominence and virilization of external genitalia. The patients were followed up for their clinical symptoms and signs, hormone profile, and adrenal image. The genomic deoxyribonucleic acids of the patients and their parents were isolated. 11β-hydroxylase gene （CYP11B1） was amplified by polymerase chain reaction and directly sequenced. Results Hormone tests showed that serum cortisol was in the low limit of normal range, whereas the concentrations of adrenocorticotropic hormone, testosterone and progesterone were much higher than those of normal adult females. There were obvious adrenal hyperplasia and advance of bone age. After 11 months of treatment with dexamethasone, the skin pigment became regressed; the breast, uterus and ovary gradually developed and normal menstrual cycle started while the manifestations of virilization did not change. A single point mutation of CYP11B1 （R454C, GGC → TGC） in all the members of this family was detected. The sisters were homozygous and their parents were heterozygous. Conclusions The clinical manifestation of 11β-OHD is complicated. The manifestation of virilization could not regress after treatment with dexamethasone. The novel missense mutation of CYP11B1 （R454C, GGC → TGC） is the pathogenesis of 11β-OHD at least in some Chinese patients.

Expression and identification of type 1 diabetes associated autoantigen IA-2

s To obtain prokaryotic expressed IA-2 recombinant protein and to identify its immunological activity Methods The complimentary DNA (cDNA) coding for the intracytoplasmic part of IA-2 (IA-2ic) was amplified from human fetal brain RNA, and was subcloned into the PinPoint Xa-1 T vector to construct recombinant expression plasmid, and was then expressed in E coli JM109 cells as a fusion protein with a biotinylated peptide sequence at the aminoterminus The biotinylated fusion protein was then purified by affinity chromatography and was subsequently dialyzed Finally, its immunogenicity was evaluated by enzyme linked immunosorbent assay (ELISA) Results The purified IA-2ic fusion protein resolved on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) as a single Coomassie brilliant blue stained band with a molecular weight of 59 kDa and its immunogenicity was confirmed by ELISA Conclusions E coli expressed IA-2ic fusion protein has immunological activity It can be used for detection of IA-2 autoantibodies (IA-2A) and for further studies on type 1 diabetes in future

The effectiveness of zinc supplementation in men with isolated hypogonadotropic hypogonadism

A multicenter, open-label, randomized, controlled superiority trial with 18 months of follow-up was conducted to investigate whether oral zinc supplementation could further promote spermatogenesis in males with isolated hypogonadotropic hypogonadism （IHH） receiving sequential purified urinary follicular-stimulating hormone/human chorionic gonadotropin （uFSH/hCG） replacement. Sixty-seven Chinese male IHH patients were recruited from the Departments of Endocrinology in eight tertiary hospitals and randomly allocated into the sequential uFSH/hCG group （Group A, n = 34） or the sequential uFSH plus zinc supplementation group （Group B, n = 33）. In Group A, patients received sequential uFSH （75 U, three times a week every other 3 months） and hCG （2000 U, twice a week） treatments. In Group B, patients received oral zinc supplementation （40 mg day-1） in addition to the sequential uFSH/hCG treatment given to patients in Group A. The primary outcome was the proportion of patients with a sperm concentration 〉1.0 × 106 ml-1 during the 18 months. The comparison of efficacy between Groups A and B was analyzed. Nineteen of 34 （55.9%） patients receiving sequential uFSH/hCG and 20 of 33 （60.6%） patients receiving sequential uFSH/hCG plus zinc supplementation achieved sperm concentrations ≥1.0 × 106 ml-1 by intention to treat analyses. No differences between Group A and Group B were observed as far as the efficacy of inducing spermatogenesis （P = 0.69）. We concluded that the sequential uFSH/hCG plus zinc supplementation regimen had a similar efficacy to the sequential uFSH/hCG treatment alone. The additional improvement of 40 mg day-1 oral zinc supplementation on spermatogenesis and masculinization in male IHH patients is very subtle.

Estrogen receptor gene polymorphisms and bone mineral density in Chinese postmenopausal women

Objective To investigate the relationships between the polymorphisms of estrogen receptor (ER) gene, bone mineral density (BMD) and bone biochemical markers in Chinese postmenopausal women. Methods BMD of lumbar spine and femoral neck were measured using dual-energy X-ray absorptiometry (DEXA)in 186 Chinese postmenopausal women. The PvuⅡ and XbaⅠ polymorphisms of the ER gene were detected using polymerase chain reaction (PCR). Bone biochemical markers, serum alkaline phosphatase, osteocalcin and pyridinoline were measured by ELISA. Results The femoral neck(FN) BMD (Z score) was higher in pp compared to Pp (-0.01±0.12 vs. -0.35±0.09, P<0.05) while lumbar spine BMD (Z score) was higher in XX type compared to Xx and xx genotypes (0.01±0.45 vs -1.53±0.17, -1.29±0.10, P<0.001 and 0.001, respectively). Women without Px haplotype (n=79) had a higher BMD Z-score for the lumbar spine (-1.03±0.14 vs -1.45±0.11, P<0.05) and femoral neck (-0.01±0.11 vs -0.31±0.09, P<0.05) than those who had it (n=107). Conclusions The present study suggested that the pp and XX genotypes of ER gene might play a certain role in maintaining FN and lumbar spine BMD. ER genotypes without Px haplotype might be favorable to bone mass, while those with it might exert some harmful effect on bone mineral density.