Hum Hered 1991;41:347-350

© 1991 S. Karger AG. Basel (XX)I-5652/91 /0415-0347 $2.75/0

Haptoglobin Phenotypes in Diabetes mellitus and Diabetic Retinopathy Tanuja Chandraa , C.N. Lakshmia , T. Padmaa, M. VidyavathP, M. Satapathyb a Department of Genetics, Osmania University; h Sarojini Devi Eye Hospital and Institute of Ophthalmology, Hyderabad, India

Key Words. Diabetes mellitus • Diabetic retinopathy • Haptoglobin types

Introduction

Diabetic retinopathy (DR) is a progres­ sive microangiopathic disorder of the reti­ na occurring usually in prolonged diabetes mellitus (DM) both of insulin-dependent (type I) and noninsulin-dependent (type II) types. Basically, two types of retino­ pathy have been described, viz. (1) simple or background DR (BDR) where veins get dilated and microaneurysms are formed, and (2) proliferative DR (PDR) where new blood vessels are formed to compen­ sate the vascular damage [Duke Elder, 1970]. It is interesting to note that all dia­ betics are not prone to retinopathy and it affects also patients with a short history of

diabetes. The risk factors which predis­ pose diabetics to retinopathy may include genetic constitution, ageing, and anatomic and physiologic variations in the eyes of the affected individuals. Haptoglobin (HP) is a serum glycopro­ tein with a functional involvement in in­ flammatory and immunologic processes. HP types have been found to be associated with a number of diseases [Giblett, 1969; Prokop and Uhicnbruck, 1969; Sutton, 1970; Padma and Murty, 1983; Norrgard et al., 1984; Rantapaa et al., 1985; Suryaprabha et al., 1987; Frohlander, 1988]. Reports on HP phenotypes in DM are varied, claiming absence of association [Simpson et al., 1962; Jorgensen and Hop-

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Abstract. An analysis of haptoglobin (HP) phenotypes in 81 cases of diabetes mellitus (DM) without retinopathy and 122 cases with diabetic retinopathy (DR) were studied in relation to 180 normal and healthy controls matched for age and sex. A significant de­ crease in HP 2-1 frequency was found, suggesting protection for heterozygotes in both DM and DR (with a relative risk of about 0.31). As an acute-phase reactant HP may be functionally involved in the etiology of DM and DR. which are associated with immuno­ logic and inflammatory processes, respectively. No significant differences were found with respect to sex, age at onset, duration of DR, types of DM and DR, and family history.

Chandra/Lakshmi/Padma/Vidyavathi/Satapathy

348 Tabic 1. Family history of DM among patients with DM and DR Condition

Familial

Nonfamilial

n

%

n

%

PDR BDR DR DM

52 20 72 32

61.9 52.6 59.0 39.5

32 18 50 49

38.1 47.4 41.0 60.5

84 38 122 81

DR + DM DR 1 DM I

104 51.2 33 67.3 22 45.8

99 48.8 16 32.6 26 54.2

203 49 48

DR II DM II

39 10

53.4 30.3

34 46.6 23 69.7

73 33

55

56.7

42 43.3

97

49

46.2

57 53.8

106

DR I + DM I DR II + DM II

Total

X?

0.93 7.42b

Material and Methods

_ 4.57a

4.89u

2.22

a p

Haptoglobin phenotypes in diabetes mellitus and diabetic retinopathy.

An analysis of haptoglobin (HP) phenotypes in 81 cases of diabetes mellitus (DM) without retinopathy and 122 cases with diabetic retinopathy (DR) were...
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