C. S. Cockram

Factor analysis of the metabolic syndrome: obesity vs insulin resistance as the central abnormality.

OBJECTIVES: To evaluate whether there is one central abnormality contributing to the conditions associated with the metabolic syndrome (MES), or whether one abnormality is contributing on multiple levels.METHODS: We recruited 145 Chinese subjects aged 17–68 y with varying degrees of insulin-sensitivity (IS): 33 healthy, 59 with type 2 diabetes mellitus, 32 essential hypertensives and 21 dyslipidaemics. IS was evaluated by the short insulin sensitivity test using a 0.1 U/kg intravenous bolus dose of insulin. Blood pressure, anthropometric measures and biochemical parameters associated with IS were also measured. Exploratory factor analyses (EFA) were performed in the entire group of 145 subjects and in the 76 with normal glucose tolerance.RESULTS: EFA in all 145 subjects defined three distinct, independent factors. Factor 1 was interpreted as general and central adiposity, impaired IS and glucose intolerance, Factor 2 was associated with hypertension and general and central obesity, whilst Factor 3 was strongly related to low HDL-cholesterol and high triglyceride concentrations and weakly to waist circumference. In patients with impaired glucose tolerance, only two factors were identified; factor 1 related to reduced IS, impaired glucose tolerance, dyslipidaemia and general and central adiposity, and factor 2 which was related to blood pressure and general and central adiposity.CONCLUSIONS: These models suggest that the clustering of variables in MES is a result of multiple factors linked by adiposity and not a single aetiology. Furthermore, increases in blood pressure are related to obesity in these Chinese subjects rather than decreased IS per se.

In vivo and in vitro sodium pump activity in subjects with thyrotoxic periodic paralysis

OBJECTIVE--To examine whether sodium pump activity plays a part in the pathogenesis of thyrotoxic periodic paralysis. DESIGN--Measurement of platelet sodium-potassium ATPase and in vivo sodium pump activities in healthy subjects and thyrotoxic subjects with and without paralysis. SETTING--University hospital in Hong Kong. SUBJECTS--21 healthy subjects, 23 untreated thyrotoxic subjects, 13 untreated men with periodic paralysis, seven treated thyrotoxic subjects, and six treated men with periodic paralysis. MAIN OUTCOME MEASURES--Platelet Na+, K(+)-ATPase activity and plasma rubidium concentration after oral loading. RESULTS--Median (range) platelet Na+, K(+)-ATPase activity in thyrotoxic subjects was 253 (169-821) mumol inorganic phosphate/h/g protein--significantly higher than that in healthy subjects (134 (81-180) mumol/h/g protein; p less than 0.001). Na+, K(+)-ATPase activity in those with periodic paralysis was 374 (195-1196) mumol/h/g protein, again significantly higher than that in healthy subjects (p less than 0.001) and that in other thyrotoxic subjects (p less than 0.01) despite similar degrees of hyperthyroidism. Activities in treated thyrotoxic subjects with and without periodic paralysis were 148 (110-234) and 131 (86-173) mumol/h/g protein respectively. Mean (95% confidence interval) plasma rubidium concentration five hours after oral administration in thyrotoxic subjects (7.0 (6.6 to 7.5) mumol/l) was significantly lower than in healthy subjects (10.2 (9.5 to 10.9) mumol/l; p less than 0.001) and higher than in those with periodic paralysis (6.0 (5.7 to 6.3) mumol/l; p less than 0.01). CONCLUSIONS--Sodium pump activity in untreated subjects with periodic paralysis is higher than in other thyrotoxic subjects, and this may be responsible for the hypokalaemia.

The prevalence of diabetes, association with cardiovascular risk factors and implications of diagnostic criteria (ADA 1997 and WHO 1998) in a 1996 community-based population study in Hong Kong Chinese

SUMMARY

Comparison of enalapril and nifedipine in treating non-insulin dependent diabetes associated with hypertension : one year analysis

OBJECTIVES--To compare the efficacy, safety, and tolerance of enalapril and nifedipine in hypertensive patients with non-insulin dependent diabetes. DESIGN--One year double blind follow up of patients randomly allocated to either enalapril or nifedipine with matching placebos for the alternative drug. SETTING--Metabolic Investigation Unit, Hong Kong. SUBJECTS--102 patients were randomised: 52 to nifedipine and 50 to enalapril. At baseline 44 patients had normoalbuminuria, 36 microalbuminuria, and 22 macroalbuminuria. MAIN OUTCOME MEASURES--Blood pressure, albuminuria, and parameters of renal function and glycaemic control. RESULTS--In patients who completed one years treatment the median dose required by the nifedipine group (n = 49) was 60 mg/day; seven (14%) required additional diuretics. Of 41 patients given enalapril, 37 required the maximum dose (40 mg/day) and 27 (76%) required diuretics. At one year mean arterial blood pressures were similar in both groups. Albuminuria fell by 54% in the enalapril group and 11% in the nifedipine group (p = 0.006). Fractional albumin clearance ratio fell by 47% in the enalapril group and increased by 3% in the nifedipine group (p = 0.009). Creatinine clearance fell similarly in both groups but plasma creatinine concentration was increased by 20% in the enalapril group versus 8% in the nifedipine group (p = 0.001). CONCLUSION--Patients taking enalapril often required diuretics to control blood pressure. Enalapril reduced proteinuria significantly more than nifedipine in the microalbuminuric and macroalbuminuric patients but increased plasma creatinine concentrations. Longer follow up is required to clarify the importance of enalaprils antiproteinuric effect.

Obesity, albuminuria and hypertension among Hong Kong Chinese with non-insulin-dependent diabetes mellitus (NIDDM).

A total of 412 Hong Kong Chinese diabetic patients were studied on at least two occasions 8-16 weeks apart. Although 28% were insulin-treated, only 3.6% had insulin-dependent diabetes (IDDM). In the remaining 397 patients with non-insulin-dependent diabetes (NIDDM), the mean (s.d.) body mass index (BMI) was 24.4 +/- 3.2 kg/m2 in females and 24.2 +/- 3.2 kg/m2 in males. Obesity was present in 17% of males (BMI > 27 kg/m2) and 40% of females (BMI > 25 kg/m2). Established hypertension was present in 49%. Abnormal albuminuria, defined as a mean urinary albumin/creatinine (UA/Cr) ratio greater than 5.4 mg/mmol based on two random spot urine samples, was present in 47%. On stepwise multiple regression analysis, UA/Cr ratio (R2 = 0.34, F = 65.4, P < 0.001) showed significant associations with systolic blood pressure (standardized regression coefficient beta = 0.40, P < 0.001), plasma creatinine concentration (beta = 0.27, P < 0.001) and glycosylated haemoglobin (beta = 0.20, P < 0.001). While the prevalence of hypertension increased with increasing severity of proteinuria, 40% of normoalbuminuric patients had hypertension. Among patients diagnosed before the age of 35 (n = 67), 52% were insulin-treated although only 10% were insulin-dependent. Among these NIDDM patients of young onset (n = 59), obesity was present in 25% of males and 56% of females. Overall, 18% of these patients had a blood pressure greater than 140/90 mmHg and 27% had abnormal albuminuria. In Hong Kong Chinese, diabetes mellitus is predominantly non-insulin-dependent even in the young. Obesity is more prevalent among females. Abnormal albuminuria is relatively common and is closely associated with hypertension and glycaemic control. In the light of increasing prevalence of diabetes among overseas Chinese, our findings may have important implications in the management of Chinese diabetic patients.

Phenotypic and genetic clustering of diabetes and metabolic syndrome in Chinese families with type 2 diabetes mellitus

The aim of this study was to investigate the familiality and clustering of type 2 diabetes (T2DM) and metabolic syndrome (MES) predominantly in families with young‐onset diabetes from the Hong Kong Family Diabetes Study.

Obesity and cardiovascular risk factors in Hong Kong Chinese

The purpose of this cross‐sectional study was to examine the risk associations between obesity indexes body mass index (BMI) and waist circumference (WC)], cardiovascular risk factors plasma glucose and lipids, blood pressure and urinary albumin excretion (UAE)] and morbidity conditions (Type 2 diabetes mellitus, hypertension, dyslipidaemia and/or albuminuria) in Hong Kong Chinese. Seven‐hundred and two Hong Kong Chinese subjects (18–65 years of age, 59.4% of whom had at least one morbidity condition) were recruited from the Prince of Wales Hospital, Hong Kong SAR. The measurements taken of the subjects included: height; weight; waist and hip circumferences; blood pressure; fasting plasma glucose and lipids; and 24‐h UAE. The mean BMI was 22.4 and 25.7 kg m−2 in healthy subjects and patients, respectively. The mean WC measurements of healthy subjects and patients were 77.1 and 86.4 cm in males and 71.0 and 81.8 cm in females, respectively. There were increasing trends between obesity indexes and the severity of cardiovascular risk factors and the prevalence of morbidity conditions (all P‐values for trend <0.05). Using 19.0–20.9 kg m−2 and <70 cm as a referent, subjects with a BMI of ≥25.0 kg m−2 (in both sexes) and/or a WC of ≥85 cm in males and ≥75 cm in females had an age‐adjusted odds ratio between 3.2 and 4.4 for the occurrence of at least one morbidity condition. Patients with a greater number of comorbidities also had higher BMI and WC measurements (all P‐values for the trend were <0.05 with adjustment for age and gender). Hence, despite Hong Kong Chinese being less obese than Caucasians, the intimate relationships among obesity, cardiovascular risk factors and morbidity conditions remain. Our data support using lower BMI and WC levels to define obesity and its associated health risks rather than using the criteria established from Caucasians who generally have larger body frames.

The associations of body mass index, C-peptide and metabolic status in Chinese Type 2 diabetic patients.

Background  Chinese Type 2 diabetic subjects are generally less obese than their Caucasian counterparts. We hypothesized that lean and obese Chinese Type 2 diabetic subjects have different metabolic and insulin secretory profiles. We compared the clinical features, C peptide and metabolic status between lean/normal weight and obese diabetic subjects.

Molecular genetics of diabetes mellitus in Chinese subjects: identification of mutations in glucokinase and hepatocyte nuclear factor‐1α genes in patients with early‐onset Type 2 diabetes mellitus/MODY

Aims To examine the prevalence of identified MODY‐related genes in Chinese subjects with early onset Type 2 diabetes mellitus and a positive family history of diabetes and to look for possible associations between the gene mutations and the development of diabetes.

Smoking and diabetes in Chinese men

Smoking is a major cardiovascular risk factor and cause of death. Diabetes mellitus is also associated with an increased mortality and morbidity. Evidence concerning whether smoking increases the incidence of diabetes remains conflicting. Glycaemic status and smoking habits were analysed in 3718 Chinese subjects in order to assess the possible association between smoking and risk of diabetes in the Chinese population. The World Health Organisation 1998 criteria were used for the diagnosis of glucose intolerance. Smoking was defined as current cigarette smoking or ex-smoking without regard to daily consumption. The smoking habits of the studied subjects were correlated with glycaemic status. There were 3003 (80.8%) women and 715 (19.2%) men. The mean age (SD) was 38.4 (12.8) years (median 35.0, range 12–88 years). Of the 3718 subjects, 786 (21.1%) had diabetes, 708 (19.1%) had impaired glucose tolerance, and 2224 (59.8%) had normal results. Of the 3003 women, only 87 (2.9%) were smokers. The female smokers were younger, heavier, and had higher alcohol consumption than non-smokers. The prevalence of diabetes was similar between female smokers and non-smokers after adjustment for age, body mass index, family history of diabetes, and alcohol. Of the 715 men, 175 (24.5%) were smokers. The male smokers were younger, had lower blood pressure, and higher alcohol consumption. After adjustment for age, body mass index, family history of diabetes and alcohol, the male smokers had lower blood pressure, higher one hour plasma glucose, and more diabetes. Using logistic regression analysis (stepwise forward) with age, body mass index, alcohol, smoking, and family history of diabetes as independent variables to predict the risk of having diabetes, age and body mass index are independently associated with diabetes in both men and women. In addition, smoking is independently associated with the risk of diabetes in men, the odds ratio (95% confidence interval, CI) being 1.705 (1.106 to 2.630). Family history of diabetes is independently associated with the risk of diabetes in women, and the odds ratio (95% CI) is 1.643 (1.314, to 2.053). In conclusion, it was found that smoking is independently associated with diabetes after adjustment for age, body mass index, alcohol, and family history of diabetes in Hong Kong Chinese men, the odds ratio being 1.7. The prevalence of smoking in Hong Kong Chinese women is low and its association with diabetes is inconclusive.