Sara Rani Marcus

Lipid peroxidation in type 2 diabetes mellitus

AIM: The link between hyperglycemia, enhanced freeradical activity, and the complications of diabetes is unknown. The purpose of this study is to evaluate the levels of malondialdehyde (MDA) measured as thiobarbituric acid-reactive substances (TBARS), an index of lipid peroxidation, in patients of type 2 diabetes without complications, and compare with normal subjects of the same population. METHODOLOGY: We recruited 60 type 2 diabetic subjects without complications and with poor metabolic control and 60 age-matched controls with good metabolic control. Levels of glucose, total cholesterol, HbA 1C , and MDA as TBARS were determined. RESULTS: Diabetic patients had higher levels of blood glucose (P<0.001), HbA 1C (P<0.001), and MDA (P<0.001) than control subjects. The total cholesterol of the control subjects and diabetic patients did not differ. There was no correlation between the family history in diabetics and elevation in either HbA or 1C MDA levels. CONCLUSION: Increased levels of MDA may be a useful marker of oxidative stress. The enhanced lipid peroxidation leads to an increase in free-radical activity in type 2 diabetics. This increase in free-radical activity in type 2 diabetes mellitus along with insulin resistance can lead to activation of stress-sensitive pathways, which may play an important role in the complications of diabetes.

Oxidative Stress in Obesity and Metabolic Syndrome in Asian Indians

Oxidative Stress in Obesity and Metabolic Syndrome in Asian Indians Oxidative stress is associated with the individual components of metabolic syndrome and has been implicated in the development of complications of these metabolic disorders. In this study oxidative stress levels have been compared in obese Indians (a high-risk population for diabetes and cardiovascular disorders) with and without metabolic syndrome. 30 adult normotensive, normoglycemic obese subjects and 35 adults with metabolic syndrome of either sex with BMI >23 kg/m2 were compared with 30 adult, healthy volunteers with BMI <23 kg/m2. Anthropometric parameters, blood pressure, biochemical parameters, hydroperoxides levels and total antioxidant capacity were estimated. The obese groups with and without metabolic syndrome had significantly increased anthropometric parameters like waist circumference and index of central obesity and aqueous phase hydroperoxides when compared with normal controls. The metabolic syndrome group also had significantly increased blood sugar levels, lipid profile and hydroperoxide levels when compared to obese or control groups. There was no alteration in the total antioxidant capacity in any of the groups. The Triglyceride/HDL-Cholesterol ratio (>3), a surrogate marker of insulin resistance, indicates insulin resistance in the metabolic syndrome group. The anthropometric profile, insulin resistance and oxidative stress seen in obesity are further elaborated in metabolic syndrome. Thus, the early identification of high-risk individuals based on anthropometric parameters, lipid profile, insulin resistance and indices of oxidative stress may help to prevent the development of complications of metabolic syndrome. Oksidativni Stres u Gojaznosti i Metaboličkom Sindromu Kod Indijaca Oksidativni stres dovodi se u vezu sa pojedinačnim komponentama metaboličkog sindroma i povezan je sa razvojem komplikacija u metaboličkim poremećajima. U ovoj studiji upoređeni su nivoi oksidativnog stresa kod gojaznih Indijaca (populaciji sa visokim rizikom za razvoj dijabetesa i kardiovaskularnih poremećaja) sa i bez metaboličkog sindroma. Trideset odraslih normotenzivnih, normoglikemičnih gojaznih ispitanika i 35 odraslih osoba sa metaboličkim sindromom oba pola sa ITM >23 kg/m2 poređeno je sa 30 odraslih zdravih dobrovoljaca sa ITM <23 kg/m2. Ispitivani su antropometrijski parametri, krvni pritisak, biohemijski parametri, nivoi hidroperoksida i ukupni antioksidantni kapacitet. U gojaznim grupama sa i bez metaboličkog sindroma antropometrijski parametri kao što su obim struka i indeks centralne gojaznosti i aqueous phase hidroperoksidi bili su značajno povišeni u poređenju sa kontrolnim subjektima. Grupa sa metaboličkim sindromom takođe je imala značajno povišene nivoe šećera u krvi, lipidni profil i nivoe hidroperoksida u poređenju sa gojaznom ili kontrolnom grupom. Ni u jednoj grupi nije bilo promena u ukupnom antioksidantnom kapacitetu. Odnos trigliceridi/HDL holesterol (>3), kao surogat marker insulinske rezistencije, ukazuje na rezistenciju na insulin u grupi sa metaboličkim sindromom. Antropometrijski profil, insulinska rezistencija i oksidativni stres prisutni u gojaznosti dalje se razvijaju u metaboličkom sindromu. Otud rana identifikacija osoba sa visokim rizikom na osnovu antropometrijskih parametara, lipidnog profila, insulinske rezistencije i indeksa oksidativnog stresa može doprineti sprečavanju razvoja komplikacija metaboličkog sindroma.

Oxidative Stress in Type 2 Diabetes with Iron Deficiency in Asian Indians

Oxidative Stress in Type 2 Diabetes with Iron Deficiency in Asian Indians A close relationship exists between iron metabolism, diabetes and oxidative stress. Both diabetes and redox active iron are individually known to enhance oxidative stress. However, the role of iron deficiency and oxidative stress in diabetes is not clear; hence, the levels of oxidative stress in type 2 diabetes with and without iron deficiency have been compared. Two groups of 30 patients each with diabetes were selected (one group with iron deficiency and the other group with normal iron levels) and compared with 30 normal healthy controls. The anthropometric parameters, fasting blood sugar, iron profile and oxidative stress parameters (malondialdehyde levels (index of lipid peroxidation) and serum uric acid levels (antioxidant)) were measured. While the diabetes group had significantly increased serum levels of ferritin (an acute phase reactant and antioxidant) in comparison with normal controls (P=0.040), the diabetic group with iron deficiency had decreased serum levels of iron (P =0.000), ferritin (P = 0.000) and uric acid (P = 0.006) and increased levels of malondialdehyde (P = 0.000) in comparison with diabetics without iron deficiency. This study shows an increase in oxidative stress in the diabetic group with iron deficiency together with reduction in antioxidant levels could further promote prooxidant levels and inflammation and in turn result in the development of complications in this high-risk Asian Indian population. Oksidativni Stres u Dijabetesu Tipa 2 sa Nedostatkom Gvožđa Kod Indijaca Metabolizam gvožđa, dijabetes i oksidativni stres blisko su povezani. Dijabetes i redoks-aktivno gvožđe zasebno pojačavaju oksidativni stres. Međutim, još nije ustanovljena uloga nedostatka gvožđa i oksidativnog stresa u dijabetesu; stoga su upoređeni nivoi oksidativnog stresa u dijabetesu tipa 2 sa i bez nedostatka gvožđa. Izabrane su dve grupe od po 30 pacijenata sa dijabetesom (jedna grupa sa nedostatkom gvožđa a druga sa normalnim nivoima gvožđa) i upoređene sa 30 zdravih kontrolnih subjekata. Izmereni su antropometrijski parametri, šećer u krvi na prazan stomak, profil gvožđa i parametri oksidativnog stresa (nivoi malondialdehida (indeks lipidne peroksidacije) i nivoi mokraćne kiseline u serumu (antioksidant)). Dok su u grupi dijabetičara nivoi feritina (reaktant akutne faze i antioksidant) u serumu bili značajno povišeni u poređenju sa zdravim kontrolnim subjektima (P = 0,040), u grupi dijabetičara s nedostatkom gvožđa bili su sniženi nivoi gvožđa (P = 0,000), feritina (P = 0,000) i mokraćne kiseline (P = 0,000) u serumu u poređenju s dijabetičarima bez nedostatka gvožđa. Ova studija pokazuje da bi porast oksidativnog stresa u grupi dijabetičara s nedostatkom gvožđa uz redukciju nivoa antioksidanata mogao dodatno povećati nivoe prooksidanata i pojačati inflamaciju, što bi za posledicu imalo razvoj komplikacija u ovoj visokorizičnoj indijskoj populaciji.

Diabetes Mellitus in Asian Indian Children and Adolescents

AIM To study the clinical and metabolic profile of type 1 and type 2 diabetes mellitus in children and adolescents in a South Asian population. RESEARCH DESIGN AND METHODS Sixty children were recruited. They were divided into three groups: Group I--type 2 diabetes mellitus (DM2), Group II--type 1 diabetes mellitus (DM1), and Group III--healthy controls. The clinical history and biochemical parameters (HbA1c, serum insulin, C-peptide, triglycerides, total cholesterol and HDL-cholesterol) were recorded. Homeostasis model assessment for insulin resistance (HOMAIR) and quantitative insulin sensitivity check index (QUICKI) were calculated. RESULTS AND CONCLUSIONS Children and adolescents with DM2 had a significant family history of DM and clinical features of insulin resistance, including increased body mass index, waist:hip ratio and acanthosis nigricans. They also had decreased insulin sensitivity together with dyslipidemia of metabolic syndrome, i.e. high triglyceride, high total cholesterol and low HDL-cholesterol. The presence of these predictors of cardiovascular disorders is known to contribute to morbidity and mortality. Hence, DM2 needs to be recognized early in Asian Indian children.

Role of Retinol-Binding Protein 4 in Obese Asian Indians with Metabolic Syndrome

Role of Retinol-Binding Protein 4 in Obese Asian Indians with Metabolic Syndrome Retinol-binding protein 4 is an adipocytokine separately implicated in the development of obesity-related insulin resistance and proatherogenic lipid profile, however, its role in humans is unclear. This study was carried out to assess the role of retinol-binding protein 4 as a potential marker of metabolic syndrome in obese Asian Indians (a high-risk population for diabetes). 52 obese (BMI >23 kg/m2) Asian Indians were grouped into those with and without metabolic syndrome based on IDF criteria and compared with healthy controls. The anthropometric and biochemical parameters (fasting blood sugar, lipid profile, serum insulin, high-sensitivity C-reactive protein, and retinol-binding protein 4) were estimated. The obese groups had significantly altered adiposity indices, insulin resistance parameters (fasting blood sugar (only in the metabolic syndrome group), serum insulin, HOMA-IR and QUICKI), index of inflammation (C-reactive protein) and proatherogenic dyslipidemic profile (serum triglycerides, VLDL-cholesterol, and triglyceride/HDL-cholesterol ratio). Retinol-binding protein 4 levels were elevated in the obese groups, but were not significant. Retinol-binding protein 4 levels were correlated with anthro-pometric parameters and atherogenic lipids, while C-reactive protein was correlated with anthropometric and insulin resistance parameters in the entire group of subjects. Although these correlations were not observed in the obese groups, in the control group, retinol-binding protein 4 was correlated to the lipid parameters and C-reactive protein to adiposity indices. Thus, the role of retinol-binding protein 4 as a potential marker of metabolic syndrome is limited to the prediction of proatherogenic risk among Asian Indians. Uloga Retinol-Vezujućeg Proteina 4 Kod Gojaznih Indijaca sa Metabolićkim Sindromom Retinol-vezujući protein 4 je adipocitokin koji ima zasebnu ulogu u razvoju insulinske rezistencije u gojaznosti i proaterogenog lipidskog profila, međutim, ona kod ljudi nije razjašnjena. Ova studija izvedena je kako bi se utvrdila uloga retinol-vezujućeg proteina 4 kao potencijalnog markera metaboličkog sindroma kod gojaznih Indijaca (populacije sa visokim rizikom za šećernu bolest). Pedeset dvoje gojaznih ispitanika (indeks telesne mase > 23 kg/m2) podeljeni su na one sa i bez metaboličkog sindroma na osnovu kriterijuma IDF i upoređeni sa zdravim kontrolnim subjektima. Određeni su antropometrijski i biohemijski parametri (šećer u krvi, lipidski profil, insulin u serumu, visokoosetljivi C-reaktivni protein i retinol-vezujući protein 4). U gojaznim grupama značajno su bili izmenjeni adipozni indeksi, parametri insulinske rezistencije (šećer u krvi (samo u grupi sa metaboličkim sindromom), insulin u serumu, HOMA-IR i QUICKI), indeks inflamacije (C-reaktivni protein) i proaterogeni dislipidemijski profil (trigliceridi, VLDL-holesterol i odnos trigliceridi/HDL-holesterol u serumu). Nivoi retinol-vezujućeg proteina 4 bili su u korelaciji sa antropometrijskim parametrima i aterogenim lipidima, dok je C-reaktivni protein korelisao sa antropometrijskim kao i parametrima insulinske rezistencije kod svih ispitanika obuhvaćenih studijom. Iako ove korelacije nisu uočene u gojaznim grupama, retinol-vezujući protein 4 bio je u korelaciji sa lipidskim parametrima a C-reaktivni protein sa adipoznim indeksima. Stoga je uloga retinol-vezujućeg proteina 4 kao potencijalnog markera metaboličkog sindroma ograničena na predviđanje proaterogenog rizika kod Indijaca.

Iron, Oxidative Stress and Diabetes

Abstract Iron is a micronutrient which exists in the redox states Fe2+ and Fe3+. The easy transition between the two contributes to its metabolic functions and toxic effects. Iron is normally sequestered by binding to proteins – hemoproteins and non-heme iron proteins. Iron homeostasis is maintained by regulation at the levels of dietary uptake and gene expression of iron binding proteins – transferrin receptor and ferritin, to prevent the release of catalytically active Fe2+ ions. Free iron promotes oxidative stress by generating highly reactive hydroxyl radicals through the Fenton/Haber Weiss reactions, which react with cellular biomolecules, resulting in tissue damage. Diabetes is a metabolic disorder characterized by hyperglycemia and oxidative stress. The elevated iron levels in diabetes also elicit oxidative stress and probably mediate insulin deficiency, insulin resistance, hepatic dysfunction and decreased antioxidant defense systems. Both iron overload and deficiency enhance oxidative stress and promote the prognosis of diabetes and its complications.