[Integrin Beta 3 PlA1/PlA2 polimorphism does not contribute to complications in both type 1 and type 2 diabetes].
BACKGROUND
The glycoprotein IIIa (beta3 integrin) is an integral part of two glicoprotein receptors of platelets and, respectively, endothelium and vascular smooth muscle cells. The gene encoding the GPIIIa, a receptor for fibrinogen, vWF and fibronectin, shows polymorphism (PlA1/PlA2); the PlA2 allele has been associated with myocardial infarction, stroke and cardiovascular disease.


METHODS
Seven hundred and thirty-two subjects with type 1 diabetes and 605 subjects with type 2 were recruited. The prevalence of complications in type 1 diabetes was: microalbuminuria (uA) 17%, overt nephropathy (MA) 10%; background retinopathy (bR) 27%, proliferative retinopathy (pR) 22%; hypertension (HYP) 13%; coronary heart disease (CHD) 9%. The respective figures for type 2 diabetes were: uA 34%, MA 21%; bR 38%, pR 18%; HYP 80%; CHD 26%. A 247 bp fragment (exon 2) was amplified by PCR. For the detection of the point mutation CDGE (Constant Denaturing Gel Electrophoresis) after optimum denaturing conditions setting by DGGE (Denaturing Gradient GE) and/or RFLP by NciI digestion were employed.


RESULTS
In type 1 diabetes, PlA1PlA1/PlA1PlA2 distribution was 77/23%. No differences were found among normoalbuminuric (nA: 76/24%), microalbuminuric (uA: 79/21%) and macroalbuminuric subjects (MA: 75/25%, p=0.79) as well as among subjects with no retinopathy (Ret-) (74/26%), bR (76/24%) and pR (78/22%, p=0.81), and between HYP- (78/22%) and HYP+ (72/28%, p=0.27) as well as CHD- (76/24%) and CHD+ (75/25%, p=0.72). Systolic blood pressure, HbA1c and retinopathy were independent predictors of nephropathy. No contribution of diastolic BP, sex, BMI, duration of diabetes and PlA2 allele was found for the risk of nephropathy. In type 2 diabetes, PlA1PlA1/PlA1PlA2/PlA2PlA2 distribution was 74.4/23.3/2.3%, with no differences foud among nA (73/25/2%), uA (75/23/2%) and MA (81/17/2%, p=0.66). No significant difference was detected among subjects with Ret- (74/22/4%), bR (77/22/1%) and pR (77/22/1%, p=0.62). Also, no differences were found between HYP- (81/17/2%) and HYP+ (74/24/2%, p=0.28) as well CHD- (76/22/2%) and CHD+ (74/24/2%, p=0.93). Systolic BP, HbA1c, presence of retinopathy, gender and BMI were independent predictors of nephropathy. Diastolic BP, duration of diabetes and PlA2 allele did not contribute to the risk of nephropathy.


CONCLUSIONS
The PlA1/PlA2 polymorphism of the GPIIIa gene does not contribute to the development of nephropathy or retinopathy in type 1 and type 2 diabetes. Furthermore, no association was found between the PlA1/PlA2 polymorphism, hypertension, and coronary heart disease.
Pucci
L
L
Divisione di Endocrinologia e Metabolismo, Università di Pisa, Pisa, Italy. plaura@immr.med.unipi.it
Lucchesi
D
D
Fotino
C
C
Grupillo
M
M
Miccoli
R
R
Penno
G
G
Del Prato
S
S
D000328:Adult; D016824:Antigens, Human Platelet / Q000235:genetics*; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics*; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics*; D003925:Diabetic Angiopathies / Q000235:genetics*; D005260:Female; D006801:Humans; D039661:Integrin beta3 / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D012307:Risk Factors
D016824:Antigens, Human Platelet; C061248:ITGB3 protein, human; D039661:Integrin beta3; C083451:human platelet antigen 1b