To evaluate the significance of plasma ACTH (pACTH), serum cortisol (SC) and urinary free cortisol UFC as well as low or high dose dexamethasone suppression test in Cushing syndrome, the levels of hormones were evaluated in 136 cases of Cushing syndrome. It was found that the levels of SC and UFC were elevated in almost all the 121 patients with Cushing syndrome. The mean levels of pACTH were higher in 86 patients with Cushing disease and lower in 36 cases with adrenocortical tumor or ACTH independent nodular adrenocortical hyperplasia (AINAH) than those in normal subjects. The ACTH levels might be in normal range in many patients with Cushing syndrome, but they were higher in patients with Cushing disease and lower in the patients with adrenocortical tumor or AINAH than those of the high limit at ACTH0am in normal subjects. It was a common feature that the diurnal rhythm of hormone secretion disappeared and the hormone levels were not suppressed by low dose dexamethasone suppression test in the patients with Cushing syndrome. In more than 90% of the patients with adrenocortical tumor or AINAH the levels of SC and UFC were not suppressed by high dose dexamethasone. In 12 of clinically cured patients with Cushing disease the levels of pACTH8am, SC8am and UFC were normal or even low. The pACTH levels were low in two patients with iatrogenic Cushing syndrome. The results suggested that examinations of SC, UFC and low dose dexamethasone suppression test were very important in the diagnosis of Cushing syndrome. The pACTH level was a key parameter to distinguish Cushing disease from adrenocortical tumor or AINAH.

Eleven old male patients with hyperuricemia were collected ( hyperuricemia group,65-90 years old ).10 healthy middle-aged males ( middle-aged group,30-40 years old) and 10 healthy old males ( older group 60-70 years old ) with normal blood uric acid level were used as controls.All of the subjects were given low purine content diet ( 250 mg/d ) for 3 days followed by high purine content diet ( 800 mg/d ) consecutively for another three days.The samples of fasting blood and 24 h urine were collected for assay.The results showed that there were no significant changes of serum uric acid ( UA ) concentration in three groups after low purine content diet.But the levels of serum UA in three groups all increased significantly after high purine content diet,and the change was higher in hyperuricemia group than middle-aged group [ ( 507.7 ± 108.1 vs 378.9 ± 80.1 ) μmol/L,P＜0.05 ].24 h urine uric acid excretion in three groups was all significantly decreased after low purine content diet and increased after high purine content diet.After high purine content diet,24 h urine uric acid was lower in hyperuricemia group than middle-aged group [ ( 2.99 ± 1.21 vs 3.62 ± 1.02 ) mmol/24 h,P＜0.05 ].Blood urea nitrogen levels in all subjects decreased after low purine content diet and increased after high purine content diet ( P＜0.05 or P＜0.01 ).Creatinine clearance rate in hyperuricemia group was decreased after high purine content diet compared with baseline [ (75.3 ± 20.3 vs 80.7 ±20.0) ml/min ],and there were no significant changes in other groups after low and high purine content diet.24 h urine protein in hyperuricemia group was higher than middle-aged group ( P＜0.05 ),and increased after high purine content diet with significant difference ( P＜0.05 ).These results suggest that high purine content diet and decreased by renal uric acid clearance mainly contribute to hyperuricemia in old people.

Objective To evaluate the safety of mefformin in the treatment of elderly type 2 diabetes mellitus(T2DM). Methods Two hundred and forty-three cases of elderly T2DM hospitalized from Jan.1996 to Dec. 2006 were reviewed; the changes of fasting blood glucose(FBG), postprandial blood glucose (PBG), glycosylated hemoglobin (HbA1c), liver and renal function and blood lactic acid were evaluate before and after treatment. Results The mean time of treatment with mefformin was (6.6±3.9) years (3 months-21 years)in these 243 cases. The levels of FBG, PBG and HbAlc significantly reduced after treatment with mefformin only in 43 cases (17.7%), mefformin combined with other oral hypoglycemic drugs in 124 cases (51.0%) and mefformin combined with insulin in 76 cases (31.3%). There was only 18.1% of the cases with normal range ( > 80 ml/min) of creatinine clearance rate (Ccr), and 25.8% of the cases with Ccr≤50 ml/min. The liver and renal function as well as the blood lactic acid had no significant change after treatment no matter in total cases or in different groups separated by Ccr.Conclusions Mefformin is safety in the treatment of elderly T2DM patients. Ageing is not the contraindication of mefformin. To the patients with high risk, we should monitoring the level of blood lactic acid.

Objective To study the outcomes and influencing factors of the conversion from normal glucose tolerance -hyperinsulinemia (NCT-HINS) to diabetes in the population of a community in Beijing.Methods All the subjects investigated received 75 g oral glucose tolerance test (OGTT) for diabetes screening carried out in May, 2006 and May, 2008. Data were calculated to analyze the outcomes and influencing factors of the conversion. HINS was diagnosed if fasting serum insulin & 15 mIU/L and/or 2-hour serum insulin after glucose loading ≥ 80 mIU/L Results The prevalence of NGT-HINS in the community in 2006 and 2008 was 5.28% and 8.67% (P<0.01) respectively and that of diabetes mellitus (DM) and impaired glucose regulation (IGR) was 3.52% , 6.56% in 2006 and 4.42% ,6.47% in 2008.The probability of the conversion from NGT-HINS to IGR and DM was 18.6% and 2.3% , being much higher than that from normal glucose tolerance- normoinsulinemia (NGT-NINS) (5.4% and 0.7% , P <0.01). However, the probability of the conversion from NGT-HINS to DM was 2.3% , which was much lower than that from IGR (26.3% , P <0.01). The reason might be that individuals with NGT-HINS had a higher waist circumference, BMI, fasting plasma glucose, 2 h plasma glucose and TG but a lower HDL-C than individuals with NGT-NINS in 2006. The HOMA β-cell function index/HOMA insulin resistance index (HBCI/IR) of individuals with NGT-HINS was much lower than that of individuals with NGT-NINS, but much higher than that of individuals with IGR. Logistic regression analysis showed that age, TG and HBCI/IR were the major influencing factors of the conversion from NGT to glucose metabolic disorders.Conclusions The probability of conversion from NGT to DM was increased remarkably when HINS was diagnosed. The reason might be that individuals with NGT-HINS suffered more metabolic risk factors and had a decreased β-cell function. Therefore, individuals with NGT-HINS should be paid attention to in diabetes prevention study.

Objective:To investigate the relationship between glycemic variability and glycosylated hemoglobin (HbA1c) level during follow-up in elderly male patients with type 2 diabetes.Methods:Retrospective cohort study. A total of 200 elderly male patients who received continuous glucose monitoring from January 2007 to January 2011 were recruited in the Second Medical Center of PLA General Hospital. The subjects were divided into two groups according to baseline mean amplitude of glycaemic excursion (MAGE) level, including MAGE <3.9 mmol/L group ( n=114) and MAGE ≥3.9 mmol/L group ( n=86). The correlation between baseline MAGE and mean HbA1c during follow-up were evaluated by univariate Pearson correlation analysis and multivariate linear regression analysis. Results:Baseline characteristics including age, body mass index, waist circumference, smoking, drinking, fasting blood glucose, blood lipid and blood pressure were comparable between MAGE <3.9 mmol/L group and MAGE ≥3.9 mmol/L group. The average follow-up period was 12.5 years. The mean HbA1c during follow-up in MAGE ≥3.9 mmol/L group was significantly higher than that in MAGE <3.9 mmol/L group (7.23%±0.72% vs. 6.91%±0.77%, t=-2.94, P=0.004). The proportion of mean HbA1c <7.0% during follow-up in MAGE ≥3.9 mmol/L group was 44.2% (38/86), which was significantly lower than that in MAGE <3.9 mmol/L group [60.5% (69/114), χ 2=5.26, P=0.022]. In univariate analysis, MAGE at baseline was correlated with the mean HbA1c during follow-up ( r=0.306, P<0.001). Multivariate linear regression analysis suggested that the baseline MAGE remained an independent influential factor of mean HbA1c ( β=0.09, 95% CI: 0.03 to 0.15, P=0.006, R2=0.31) after several confounding factors were adjusted. Conclusions:With the increased glycemic variability at baseline, mean HbA1c level during follow-up is accordingly elevated. The glycemic variability at baseline is independently related to mean HbA1c level during follow-up in elderly male patients with type 2 diabetes.