Correlations between plasma insulin and body weight in obesity,anorexia nervosa and diabetes mellitus

Summary Determinations of plasma insulin levels (IRI) were performed in 79 patients before and after a quick intravenous glucose load (0.33 g/kg body weight). The patients were divided in normals (N), underweight patients (M), obese (O), latent diabetics (D1) and overt diabetics (D2), obese latent diabetics (OD1) and obese diabetics (OD2). The body weight varied from 59 to 290 per cent of ideal body weight and the age from 14 to 75 years. We were unable to find any significant correlation between basal IRI values and body weight. We found significant correlations between IRI values obtained after glucose administration and body weight. The insulinogenic index rises with increasing body weight in all subjects, in non diabetics (N-M-O) as well as in diabetics (D1-D2-OD1-OD2). In undernutrition due to anorexia nervosa, the basal plasma IRI and the plasma IRI increase after the glucose load are normal in the studied patients. Overt diabetic patients (D2 and OD2) were significantly older than non diabetic patients having the same body weight (N-O). The insulinogenic index fell with increasing age in obese and in diabetic patients. The correlations between plasma IRI and blood sugar are discussed.This study has been performed with the support of the Fondation pour la Recherche Médicale Française at the Clinique endocrinologique (Prof.F. Stephan) and the Laboratoire d'Immunologie générale (Prof. R. Minck), C.H.U. de Strasbourg F 67.     

Associations between smoking,glucose metabolism and lipid levels: A cross-sectional study

AimsThe aim of this study was to investigate glucose profiles assessed by oral glucose tolerance tests (OGTT), fasting glucose, and lipid profiles among smokers, ex-smokers and never-smokers.Materials and methodsThe study design used was a cross-sectional analysis of data from several years of the NHANES (National Health and Nutrition Examination Survey) from 2005 to 2014. A total of 12,460 participants with measures of OGTT, triglycerides, LDL-cholesterol and HDL-cholesterol were included for the data analysis. Outcomes were all assessed in an unadjusted and in an adjusted gender analysis. A GLM model was used to assess 2-hour OGTT, fasting plasma glucose, difference between fasting plasma glucose and OGTT, HbA1c, HDL-cholesterol, LDL-cholesterol, and triglyceride in relation to current smoking, ex-smoking and never smoking. The effects were adjusted with covariates: gender, BMI, age, alcohol usage, educational level and ethnicity.ResultsThe OGTT results was lower for the group smoking (−10.1 [−13.2; −7.1], p < 0.001), and no effect was observed from ex-smoking (−2.7 [−5.7; 0.8], p = 0.08). Fasting glucose was not different for smokers (−0.2 [−1.6; 1.2], p = 0.80) or ex-smokers (0.1 [−1.3; 1.5], p = 0.90). For smokers', triglycerides (1.2 [1.1; 1.3], p < 0.001), LDL-cholesterol (7.7 [6.0; 9.3], p < 0.001) were increased and HDL-cholesterol was decreased (−2.1 [−2.8; −1.5], p < 0.001).ConclusionsAlthough this study is cross-sectional and cannot, by the same nature of the design, prove a cause-effect relationship, the present results indicate that cigarette smoking may be associated with factors that are adversely related to the metabolic syndrome. But the evidence from our results are not unanimous pointing in the same direction as 2-hour OGTT measurements are considerably lower in participants smoking.     

Adverse effects of obesity on lipid and lipoprotein levels in insulin-dependent and non-insulin-dependent diabetes

We studied the association of obesity with lipid and lipoprotein concentrations in 92 patients (49 men, 43 women) with insulin-dependent diabetes (IDDM), in 305 patients (152 men, 153 women) with non-insulin-dependent diabetes (NIDDM), and in 122 nondiabetic control subjects (65 men, 57 women). Obesity (body mass index, BMI) was associated with abnormal lipid and lipoprotein levels only in the presence of diabetes, and lipid and lipoprotein changes were substantially more abnormal in patients with NIDDM than in patients with IDDM. In men and women with NIDDM, obesity was associated with low high-density lipoprotein (HDL) and HDL2 cholesterol and high total, low-density lipoprotein (LDL), and very low-density lipoprotein (VLDL) triglyceride concentrations. In men with IDDM, obesity was related only to low HDL and HDL2 cholesterol and in women with IDDM to low HDL3 cholesterol. BMI and diabetes status had a statistically significant interaction (analysis of variance) with respect to HDL and HDL2 cholesterol and total and VLDL triglycerides, indicating that the effects of obesity on lipids and lipoproteins were more severe in patients with diabetes than in nondiabetic subjects. In conclusion, obesity and diabetes status have an unfavorable interaction that results in multiple pathologic lipid and lipoprotein changes, particularly in NIDDM.     

Pituitary resistin gene expression: effects of age, gender and obesity

Resistin is a new adipocytokine which is expressed in rat, mouse and possibly human adipose tissue. Its putative role as a mediator of insulin resistance is controversial. We hypothesized that resistin, like leptin, would have multiple roles in non-adipose tissues and we reported that resistin is expressed in mouse brain and pituitary. Moreover, resistin expression in female mouse pituitary is developmentally regulated and maximal expression occurs peripubertally. Although the role of endogenous resistin in mouse brain and pituitary has not been determined, our data suggest that resistin could be important in the postnatal maturation of the hypothalamic-pituitary system. In the present study we compared the ontogeny of resistin gene expression in the pituitary of male and female mice using semi-quantitative RT-PCR analysis. We show that resistin expression is developmentally regulated in the pituitary of male and female CD1 mice. However, significant gender differences were evident (male > female at postnatal day 28 and 42) and this was not modified by neonatal treatment of female pups with testosterone. Since resistin expression in adipose tissue is also influenced by obesity, we evaluated resistin expression in fat, brain and pituitary of the obese ob/ob mouse. Resistin mRNA was significantly increased in both visceral and subcutaneous adipose depots in postnatal day 28 ob/ob mice compared to controls, but pituitary resistin expression was significantly reduced. In contrast to the prepubertal levels, and in agreement with other reports, adipose resistin expression was reduced in adult ob/ob mice. In a third set of experiments we examined the influence of food deprivation on pituitary and fat resistin mRNA. Resistin gene expression was severely down-regulated by a 24-hour fast in adipose and pituitary tissue but not in hypothalamus. In conclusion, pituitary resistin expression is age- and gender-dependent. In ob/ob mice, and in fasted mice, resistin is regulated in a tissue-specific manner. Thus in visceral fat obesity increases but starvation decreases resistin mRNA. In contrast, pituitary levels are decreased in the presence of both high (ob/ob) and low (fasting) adipose stores. Further studies are required to define the unexpected hormonal regulation of resistin gene expression in the pituitary.     

The association of age,gender, ethnicity,family history,obesity and hypertension with type 2 diabetes mellitus in Trinidad

AimsTo assess the impact of risk factors such as age, gender, ethnicity, family history, body mass index (BMI), waist circumference and hypertension, on the development of type 2 diabetes mellitus in the Trinidadian population.Materials and MethodsA cross-sectional case control study comprised 146 non-diabetics and 147 type 2 diabetics ≥18 years of age, from North Central, South West and Eastern regions of Trinidad.ResultsCross-tabulations revealed a significant difference between type 2-diabetes and age at p < 0.01, and between type 2 diabetes and family history, ethnicity, waist circumference and hypertension at p < 0.05. Logistic regression showed age to be the most influential risk factor. The systolic blood pressure specifically showed a significant difference at p < 0.05, with the mean values for non-diabetics and type 2 diabetics being, 130.62 (±2.124) and 141.35 (±2.312), respectively. No significant difference was observed between type 2 diabetes and gender and BMI.ConclusionsAge was the most significant risk factor of type 2 diabetes. Therefore it can be concluded that family history, ethnicity, waist circumference and hypertension are more significant risk factors of this disease than BMI and gender in the Trinidadian population.     

An association between obesity and the prevalence of colonic adenoma according to age and gender

Background Epidemiologic data on obesity as a risk factor for colonic adenoma with respect to gender have not yet been confirmed. Here, we aimed to compare the prevalence of colonic adenoma and of advanced polyps in age-stratified men and women at baseline, to examine the role of body mass index (BMI) on colonic adenoma risk according to age and gender, and to examine the influence of menopausal status. Methods A total of 1744 asymptomatic patients (946 men, 798 women) who underwent colonoscopy for cancer screening at Ewha Mokdong Hospital, Seoul, Korea, between February and June 2005, were eligible. BMI was assessed, and histology, size, and location of the adenoma were examined for each patient. Women were interviewed for menopausal status and a history of hormone replacement therapy. Results A significant increase in the prevalence of colonic adenoma and of advanced polyps was found to occur with age (P for trend < 0.01). The prevalences of adenoma and advanced polyps were higher in men in most age groups (P < 0.01), but no significant difference in prevalences was observed between genderes in patients 70 years of age or older. Moreover, a positive association between BMI and the prevalence of colonic adenoma and advanced polyps was shown in relatively young individuals of both gender (men in their thirties, P < 0.05; women in their forties, P < 0.05), and premenopausal women according to hormonal status (P = 0.01). Conclusions Our data suggest that obesity increases the risk of colonic adenoma in relatively young people and in premenopausal women subject to estrogen effects.     

肠道菌群与肥胖和糖尿病的关系

人的胃肠道内寄居着种类繁多的单细胞微生物,称为肠道菌群.基因、出生方式、婴幼儿喂养模式、抗生素应用、卫生居住条件以及长期的饮食习惯有助于塑造肠道菌群的组成.越来越多的动物和人体研究表明肠道菌群与肥胖和2型糖尿病密切相关.肠道菌群可通过宿主能量代谢、免疫系统及炎性反应等影响代谢综合征及2型糖尿病的发生、发展.干预肠道菌群有可能成为防治肥胖及糖尿病的新靶点.     

Inhibition of dipeptidyl peptidase-4 reduces glycemia, sustains insulin levels, and reduces glucagon levels in type 2 diabetes

The stimulation of insulin vs. inhibition of glucagon secretion in relation to the antidiabetic action of glucagon-like peptide-1 (GLP-1) is not established. Here, the influence of a 4-wk increase in circulating GLP-1 by inhibition of dipeptidyl peptidase-4 (DPP-4) on 24-h glucose and insulin and glucagon responses to breakfast was studied in subjects with dietary controlled diabetes [age: 65 +/- 8 yr (SD), body mass index: 27.3 +/- 3.3 kg/m(2), fasting plasma glucose: 9.0 +/- 1.3 mmol/liter]. Compared with placebo (n = 19), a specific DPP-4 inhibitor [(1-[[(3-hydroxy-1-adamantyl) amino] acetyl]-2-cyano-(S)-pyrrolidine) (LAF237); 100 mg daily, n = 18] reduced fasting glucose by 0.70 mmol/liter (P = 0.037), 4-h prandial glucose excursion by 1.45 mmol/liter (P < 0.001), and mean 24-h glucose by 0.93 mmol/liter (P < 0.001). Baseline and postprandial active GLP-1 were increased by LAF237. The glucagon response to breakfast was reduced by LAF237 (glucagon levels at 60 min were 88 +/- 8 pg/ml before treatment vs. 77 +/- 5 pg/ml after; P = 0.001). In contrast, the overall insulin levels were not altered. The 4-wk reduction in glucagon correlated with the reduction in 2-h glucose (r = 0.61; P = 0.008). No such association was observed for insulin. Thus, improved metabolic control by DPP-4 inhibition in type 2 diabetes is seen in association with reduced glucagon levels and, despite the lower glycemia, unaltered insulin levels.     

Relations between anthropometric data, age, obesity and nutrition

979 obese men and women (236 men and 743 women) as well as 341 normal-weight probands (149 men and 192 women) aged 18-59 were examined for nutritive, clinical, and anthropometric data. Nearly all of the anthropometric data investigated by us correlate with the increase of body weight. (height, breadth and depth of the chest, biacromial and bitrochanter breadth, height in the sitting position and height of trunk, measurement of skinfold thickness). Height of the body and height in sitting position, depth of the chest and weight behaviour were found age-dependent with men. The investigations proved the increase in body weight to be caused by an increase in body fat. Thus precise as possible knowledge about the individual body composition is an important factor for the assessment of the nutritional state. This enables an easier and more precise differentiation between overweight and degrees of obesity.     

Controlling lipid levels in diabetes

Coronary heart disease (CHD) is associated with a 2- to 4-times greater risk of morbidity and mortality in patients with type 2 diabetes than in non-diabetic individuals. Dyslipidaemia is an important CHD risk factor in diabetic patients. The key atherogenic features of diabetic dyslipidemia are elevated levels of serum triglycerides, low levels of high density lipoprotein (HDL) cholesterol, and the preponderance of small, dense low density lipoprotein (LDL). As a result, treatment guidelines for diabetic dyslipidaemia recommend elevated LDL cholesterol and triglyceride levels and low HDL cholesterol levels as targets of therapy. Unfortunately, however, these lipid abnormalities often persist dispite best efforts to control hyperglycaemia, improve diet, and increase physical exercise, and therefore demand specific therapeutic intervention. Statins are the first choice for LDL cholesterol lowering as they are effective and well tolerated, and do not have adverse effects on glycaemic control. Furthermore, recent evidence suggests that statins may also be employed to treat moderately elevated levels of triglycerides. An increasing number of primary and secondary prevention trials have shown that lipid-lowering therapy with statins can significantly reduce the risk of CHD events in patients with diabetic dyslipidaemia.     

Study on lipid metabolism in obesity diabetes

Knowing the relationship between obesity and diabetes, the purpose of our work was to study the alterations in lipid metabolism as measured by continuous indirect calorimetry in the course of a 100-g oral glucose-tolerance test in groups of obese patients without and with diabetes, respectively. Seventy-nine obese patients participated in the study. They were divided into four groups according to the degree of carbohydrate intolerance: group A, normal glucose tolerance; group B, impaired glucose tolerance; group C, diabetes with hyperinsulinemic response to the load; group D, diabetes with impaired insulin response. All four groups of patients presented an increase in lipid oxidation, both in the fasting state and during the three-hour glucose tolerance test, when compared to the control group. The lipid oxidation rate was roughly parallel to plasma free fatty acid (FFA) levels. The contribution of lipids to energy expenditure was higher in obese as compared to control subjects. These observations suggest that the larger part taken by lipids in the energy metabolism of both nondiabetic and diabetic obese humans is a consequence of their increased fat stores and that the resulting decrease in carbohydrate metabolism may lead, as a late consequence, to alterations in glucose tolerance. The latter may result in delayed glucose storage and oxidation in the obese patient.     

血清脂肪甘油三酯脂肪酶水平与肥胖和糖尿病的相关性

目的通过检测肥胖和新诊断2型糖尿病患者的血清脂肪甘油三酯脂肪酶（adiposetfiglycefidelipase,ATGL）水平,探讨ATGL与糖、脂代谢的相关性。方法选取2006年8月至2009年4月在江苏大学附属医院门诊和内分泌科住院患者114例,其中男54例,女60例,年龄38-70岁。分为2型糖尿病患者66例和正常糖调节者48例,再按体质指数（BMI）是否≥25kg／m^2分为4组：2型糖尿病-超重组、正常糖调节-超重组、2型糖尿病．正常体重组和正常糖调节．正常体重组,检测空腹血糖、血脂和空腹胰岛素（FINS）、ATGL水平,并计算BMI、腰臀比、体脂含量和胰岛素抵抗指数（HOMA-IR）。分别进行t检验、直线相关分析、多元逐步回归分析。结果（1）血清ATGL水平在2型糖尿病-超重组为（239±61）μg／L,与2型糖尿病-正常体重组[（355±54）μg／L]相比,差异有统计学意义（t=22．53,P〈0．05）;而正常糖调节-超重组[（242±60）μg/L]与正常糖调节-正常体重组[（383±58）μg/L]相比,差异也有统计学意义（t=8．23,P〈0．05）。（2）简单相关分析发现,血清ATGL浓度与体脂含量、BMI、腰臀比、甘油三酯、HOMA．IR等呈负相关（r值分别为-0．271、-0．238、-0．375、-O．313、-0．164,均P〈0．05）。多元逐步回归分析发现腰臀比、体脂含量为血清ATGL的独立相关因素。结论肥胖者的血清ATGL水平明显低于正常体重者,ATGL与腰臀比、体脂含量呈独立相关,而与血糖无明显相关。     

Influences of age, gender, smoking, and family history on autoimmune thyroid disease phenotype

CONTEXT: Both genetic and environmental factors contribute to susceptibility to Graves' disease (GD) and Hashimoto's thyroiditis (HT), as well as disease manifestations. OBJECTIVE: The objective of the study was to define how endogenous/environmental factors contribute to variation in phenotype. DESIGN/SETTING: This was a multicenter cohort study. PATIENTS/OUTCOME MEASURES: We prospectively collected clinical/biochemical data as part of the protocol for a United Kingdom DNA collection for GD and HT. We investigated, in 2805 Caucasian subjects, whether age at diagnosis, gender, family history (FH), smoking history, and presence of goiter influenced disease manifestations. RESULTS: For 2405 subjects with GD, the presence of goiter was independently associated with disease severity (serum free T4 at diagnosis) (P < 0.001). Free T4 (P < 0.05) and current smoking (P < 0.001) were both independent predictors of the presence of ophthalmopathy. Approximately half of those with GD (47.4% of females, 40.0% of males) and HT (n = 400) (56.4% of females, 51.7% of males) reported a FH of thyroid dysfunction. In GD, a FH of hyperthyroidism in any relative was more frequent than hypothyroidism (30.1 vs. 24.4% in affected females, P < 0.001). In HT, a FH of hypothyroidism was more common than hyperthyroidism (42.1 vs. 22.8% in affected females, P < 0.001). For GD (P < 0.001) and HT (P < 0.05), a FH was more common in maternal than paternal relatives. The reporting of a parent with thyroid dysfunction (hyper or hypo) was associated with lower median age at diagnosis of both GD (mother with hyperthyroidism, P < 0.001) and HT (father with hypothyroidism, P < 0.05). In GD and HT, there was an inverse relationship between the number of relatives with thyroid dysfunction and age at diagnosis (P < 0.01). CONCLUSIONS: Marked associations among age at diagnosis, disease severity, goiter, ophthalmopathy, smoking, and FH provide evidence for interactions between genetic and environmental/endogenous factors; understanding these may allow preventive measures or better tailoring of therapies.     

Plasma insulin levels during pregnancy,in obesity and potential diabetes

Summary The plasma insulin was measured by a radioimmunoassay method in 48 non-pregnant or pregnant women during glucose tolerance test (100 g glucose by mouth). Each of these 2 groups included non-obese, non-diabetic women, obese females and potential diabetic patients. The non-obese, non-diabetic, non-pregnant subjects showed mean plasma insulin levels of 25.2, 77.2, 57.0, 57.8 and 44.7U/ml respectively 0, 45, 90, 135 and 180 minutes after glucose loading. The obese normoglycemic non pregnant females presented a normal fasting plasma insulin level which reaches 184.7,U/ml 45 minutes after glucose intake. The late pregnancy (7th to 9th month) did not change the plasma insulin observed in the non-obese, non-diabetic and obese women. The non-pregnant females with potential diabetes showed a normal fasting plasma insulin with a maximum of 96.9U/ml 90 minutes after the beginning of the test. In these patients between the 4th to the 9th month of the pregnancy, the maximum of 68.2U/ml was only obtained 3 hours after the glucose loading.-The physio-pathological significance of these results is discussed.

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Plasmainsulin bei Fettsucht, latentem Diabetes und Schwangerschaft

Zusammenfassung Mit einer radioimmunologischen Methode wurde das Plasmainsulin bei 48 nichtschwangeren oder schwangeren Frauen während eines Glucosetoleranztestes (100 g Glucose per os) untersucht. Jede dieser beiden Gruppen umfaßte nichtfettleibige, nichtdiabetische Frauen, fettleibige Frauen und latentdiabetische (nichtfettleibige) Frauen. Die nichtfettleibigen, nichtdiabetischen, nichtschwangeren Personen zeigten nüchtern und 45, 90, 135 und 180 Min. nach Glucosebelastung einen mittleren Plasmainsulinspiegel von 25.2, 77.2, 57.0, 57.8 und 44.7E/ml. Die fettleibigen, nichtschwangeren Frauen mit normalen Blutzuckerwerten hatten einen normalen Nüchternplasmainsulinspiegel, der 45 min nach Glucoseaufnahme auf einen Wert von 184.7E/ml anstieg. Bei den nichtfettleibigen, nichtdiabetischen und fettleibigen Frauen kam es im letzten Drittel der Schwangerschaft (7.–9. Monat) nicht zu einer Veränderung des Plasmainsulinspiegels. Die latent diabetischen, nichtschwangeren Frauen zeigten einen normalen Nüchternplasmainsulinspiegel mit einem Maximum von 96.9E/ml 90 Min. nach Beginn des Testes. Bei den Patienten mit einer Schwangerschaft zwischen dem 4. und 9. Monat wurde das Maximum des Insulinspiegel von 68.2,E/ml erst drei Stunden nach der Glucosebelastung erreicht.-Die pathophysiologische Bedeutung dieser Befunde wurde besprochen.

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Taux d'insuline plasmatique dans la gravidité, dans l'obésité et dans le diabéte potentiel

Résumé L'insuline plasmatique, mesurée par la méthode radioimmunologique, a été dosée chez 48 femmes non enceintes ou enceintes au cours de l'hyperglycémie provoquée par la prise orale de 100 g de glucose. Chacun de ces 2 groupes de patientes comprenait des femmes non obéses et non diabétiques, des patientes obéses et des femmes présentant un diabéte potentiel. Les patientes non obéses et non diabétiques présentaient en dehors de la grossesse des taux moyens d'insuline plasmatique de 25.2, 77.2, 57.0, 57.8 et 44.7U/ml respectivement 0, 45, 90, 135 et 180 minutes après la surcharge glucosée. Les patientes obèses normoglycémiques non enceintes présentaient á jeun un taux normal d'insuline plasmatique qui atteignait 184.7U/ml, 45 minutes après la prise du glucose. La grossesse au 3° trimestre ne modifiait pas les taux d'insuline plasmatique observés chez les femmes non obèses et non diabétiques et chez les patientes obèses. Les femmes avec un diabète potentiel et non enceintes présentaient à jeun un taux normal d'insuline plasmatique avec un maximum de 96.9U/ml 90 minutes après le début du test. Au cours des 2° et 3° trimestres de la grossesse chez ces patientes, le maximum de 68.2U/ml était seulement atteint 3 heures après la prise du glucose.-L'interprétation physio-pathologique de ces résultats est discutée.

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This study was supported by grants from the Fondation Médicale Reine Elisabeth, the Fonds de la Recherche Scientifique Médicale, the Eli Lilly and Co, Indianapolis and the Cyanamid International, Pearl River N.Y.

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Aspirant of the Fonds National de la Recherche Scientifique-Belgium.     

Influence of age, gender, and obesity on salicylate kinetics following single doses of aspirin

Salicylate kinetics following single, 650-mg intravenous and oral doses of aspirin were evaluated in humans in 2 studies. Complete conversion of aspirin to salicylate was assumed. The first study involved 25 young (25-40 years) and 21 elderly (66-89 years) healthy male and female volunteers. Mean salicylate clearance was lower in elderly females compared with that in young females; however, the difference between young men and elderly men was not significant. Salicylate free fraction in plasma increased significantly with age in men and women. After correction for free fraction, unbound mean clearance was reduced in elderly men compared with young men, and in elderly women compared with young women. Peak plasma salicylate concentrations after taking oral aspirin were not significantly influenced by age, and systemic availability of salicylate in all groups was complete. The second study compared 20 obese subjects (mean weight 113 kg) with 20 normal weight controls (mean weight 67 kg) matched for age, sex, height, and smoking habits. Small differences between obese and control groups were observed in total salicylate volume of distribution (Vd), unbound Vd, and mean clearance of total or unbound salicylate. Following normalization for total weight, however, values of total Vd and mean clearance were significantly smaller in obese subjects than in normal weight subjects. Rate and completeness of salicylate absorption were not influenced by obesity when aspirin was ingested, although peak levels were lower in obese subjects. If applied to multiple doses, the reduced unbound clearance of salicylate in the elderly would imply increased accumulation unless doses are appropriately adjusted downward. During long-term therapy, salicylate dosage for obese individuals should not be adjusted upward in proportion to total weight.     

Antioxidant enzyme activities in healthy Chinese adults: influence of age, gender and smoking

OBJECTIVE: Specific antioxidant enzymes play a vital role in regulating and maintaining oxidant species. The aim of this study was to determine these antioxidant enzyme activities (i.e. catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx)) in erythrocytes from a group of healthy Chinese subjects and to study the influence of age, gender and smoking habits on the enzyme activities. METHODOLOGY: Chinese healthy subjects (n = 276) were grouped according to their age range, gender differences and smoking habits. Antioxidant enzyme activities were measured spectrophotometrically using standard kinetic methods. RESULTS: There was a significant decrease in erythrocyte GPx activity in ever-smokers compared with non-smokers (47.10 +/- 1.33 mU/g haemoglobin (Hb) vs. 51.41 +/- 1.64 mU/g Hb, P < 0.05). Age-related significant increases in erythrocyte CAT and SOD activities were found in non-smokers but not in ever-smokers. There was no age-related difference in erythrocyte GPx activity in either non-smokers or ever-smokers. Among those >60 years old, erythrocyte CAT and GPx activities were significantly lower in ever-smokers than in non-smokers (29.70 +/- 3.07 mU/g Hb vs. 41.63 +/- 4.92 mU/g Hb (P < 0.05), and 47.55 +/- 2.00 mU/g Hb vs. 55.30 +/- 3.60 mU/g Hb (P < 0.05), respectively). It was also found that females had higher erythrocyte GPx activity than males but this difference did not reach significance in non-smokers. CONCLUSION: From the results of this study, it is concluded that oxidative stress seems to be present in elderly ever-smokers among the Chinese population.