Comparison of Body Mass Index with Body Fat Percentage in the Evaluation of Obesity in Chinese

Objective To evaluate the present Chinese body mass index （BMI） criteria with body fat percentage （BF%） in determining obesity in Chinese population. Methods A total of 4 907 subjects （age： 20-90 yrs） were enrolled in the baselirie survey of a longitudinal epidemiological study, and 2 638 of them were reevaluated in 5.5 years later. The Chinese BMI and WHO BF% were used to define obesity, respectively. Results The diagnostic agreement between the Chinese BMI and WHO BF% definitions for obesity was poor for both men （kappa： 0.210, 95% CI： 0.179-0.241） and women （kappa： 0.327, 95% CI： 0.296-0.358）. However, BMI had a good correlation with BF% both in men （r： 0.785, P〈0.01） and women （r： 0.864, P〈0.01）. The age and sex-adjusted relative risks （RR） for incidence of type 2 diabetes （T2DM） were significantly higher in subjects with intermediate BF% （BF%：20.1%-25% for men, 30.1%-35% for women） （RR： 2.35, 95% CI： 1.23-4.48） and high BF%（BF%〉25% for men and 〉35% for women）（RR： 2.89, 95% CI： 1.43-5.81）, or in subjects with high BMI （BMI≥ 28 kg/m2） （RR： 2.46, 95% CI： 1.31-4.63） when compared to those with low BF% （BF%≤20% for men ands〈30% for women） or low BMI （BMI〈24 kg/m^2） respectively. No difference in risk could be found in those with intermediate BMI （BMI： 24-27.9 kg/m^2） （RR： 1.44, 95% CI： 0.86-2.40）, as compared to those with low BMI （BMI〈24 kg/m^2）, whose BF% ranged widely from 7.8 to 50.3%. Conclusion BMI was correlated with BF%. Both BMI and BF% were associated with high risk for T2DM. However, BMI had its limitations in the interpretation of subjects with BMI between 24 and 27.9 kg/m^2.

Precise Microdeletion Detection of Prader-Willi Syndrome with Array Comparative Genome Hybridization

Objective Prader-Willi Sydrome （PWS） is a human disorder related to genomic imprinting defect on 15ql 1-13. It is characterized by a series of classic features such as hypotonia, hyperphagia, obesity, osteoporosis, typical facial and body dysmorphosis, hypogonadism, mental and behaviour disorders. Our study was designed to precisely detect the microdeletions, which accounts for 65%-70% of the PWS. Methods Physical and laboratory examinations were firstly performed to diagnose PWS clinically, and to discover novel clinical features. Then the patient was screened with bisulfite-specific sequencing and precisely delineated through high-density array CGH. Results With the bisulfite-specific sequencing, the detected CpG island in the PWS critical region was found homozygously hypermethylated. Then with array CGH, a 2.22 Mb type II microdeletion was detected, covering a region from MKRN3, MAGEL2, NDN, PWRN2, PWRN1, Cl2orf2, SNURF-SNRPN, C/D snoRNAs, to distal of UBE3A. Conclusions Array CGH, after the fast screening of Bisulfite-specific sequencing, is a feasible and precise method to detect microdeletions in PWS patients. A novel feature of metacarpophalangeal joint rigidity was also presented, which is the first time reported in PWS.

Intracellular Retention of Human Melanocortin-4 Receptor:A Molecular Mechanism Underlying Early-onset Obesity in F261S Pedigree of Chinese

Objective To investigate how F261S mutation identified from Chinese obese patients affects the function of melanocorfin 4 receptor (MC4R) and to analyze the obesity-related phenotypes in subjects carrying the F261S mutation. Methods F261S mutant of MC4R was generated by site-directed mutagenesis. Plasmids encoding wild-type or F261S mutant of MC4R were transfected into HEK293 and COS-7 cells to examine their functional characteristics. Signaling properties of F261S MC4R were assessed by measuring intracellular cAMP levels in response to α-MSH stimulation. Cell surface expression of F261S MC4R was compared with that of wild-type MC4R. Clinical examinations were performed in subjects carrying F261S mutation and in non-mutated controls. Results The a-MSH-stimulated reporter gene activity was significantly reduced in cells expressing F261S MC4R, with a maximal response equal to 57% of wild-type MC4R. The F261S mutation also led to a significant change in the EC50 value compared with the wild-type receptor (P〈0.01). Immunofluorescent assay revealed a marked reduction in plasma membrane localization of the MC4R in cells expressing the F261S mutant receptor. The resting metabolic rate and fat composition of the mutant carriers were not significantly different from those of the non-mutated obese controls. Conclusions The decreased response to α-MSH due to the intracellular retention of MC4R may cause early-onset obesity in the F261S pedigree of Chinese.

Synchronous primary hyperparathyroidism,follicular thyroid carcinoma,and papillary thyroid carcinoma

To the Editor:The co-existence of primary hyperparathyroidism (pHPT) and nonmedullary thyroid carcinoma (NMTC) has been reported occasionally since 1956;[1,2] meanwhile, the synchronous occurrence of pHPT and two distinct tumors (follicular and papillary thyroid carcinoma) has rarely been reported.

Primary Empty Sella Associated with Pituitary Adenoma Diagnosed by Inferior Petrosal Sinus Blood Sampling

To the Editor：Primary empty sella associated with pituitary adenoma in diabetes patients is rarely reported.Here,we report a case of this association.A 63-year-old type 2 diabetic woman was admitted to our hospital on July 4,2014.Laboratory examinations revealed HbA1c level was 8.6%.General physical examination revealed typical acromegalic features of the face [Figure 1a],hands,and feet while a static enhanced magnetic resonance imaging （MRI） examination indicated an empty sella without pituitary adenoma.Laboratory examinations revealed an elevation of urine cortisol of 24 h at 353.6 μg （reference range 28.5-214.0 μg）.