Interrelationships of microangiopathy, plasma glucose and other risk factors in 3583 diabetic patients: a multinational study

Gender differences in retinal diseases: A review

Gender medicine is a medical specialty that addresses gender differences in health and disease. Traditionally, medical research and clinical practice have often been focused on male subjects and patients. As a result, gender differences in medicine have been overlooked. Gender medicine considers the biological, psychological, and social differences between the genders and how these differences affect the development, diagnosis, treatment, and prevention of disease. For ophthalmological diseases epidemiological differences are known. However, there are not yet any gender-based ophthalmic treatment approaches for women and men. This review provides an overview of gender differences in retinal diseases. It is intended to make ophthalmologists, especially retinologists, more sensitive to the topic of gender medicine. The goal is to enhance comprehension of these aspects by highlighting fundamental gender differences. Integrating gender medicine into ophthalmological practice helps promote personalized and gender-responsive health care and makes medical research more accurate and relevant to the entire population.

Sex-Gender Differences in Diabetic Retinopathy

Diabetic retinopathy (DR) is one of the main causes of visual loss in individuals aged 20–64 years old. The aim of this study was to investigate, in a multicenter retrospective cross-sectional study, sex-gender difference in DR in a large sample of type 2 diabetic patients (T2DM). 20,611 T2DM regularly attending the units for the last three years were classified as having: (a) No DR (NDR), (b) nonproliferative DR (NPDR), or (c) preproliferative/proliferative DR (PPDR). DR of all grades was present in 4294 T2DM (20.8%), with a significant higher prevalence in men as compared to women (22.0% vs. 19.3% p < 0.0001). Among DR patients, both NPDR and PPDR were significantly more prevalent in men vs. women (p = 0.001 and p = 0.0016, respectively). Women had similar age and BMI, but longer diabetes duration, worse glycemic metabolic control, and more prevalence of hypertension and chronic renal failure (CRF) of any grade vs. men. No significant differences between sexes were evident in term of drug therapy for diabetes and associate pathologies. Conclusions: In this large sample of T2DM, men show higher prevalence of DR vs. women, in spite of less represented risk factors, suggesting that male sex per se might be a risk factor for DR development.

Sex differences in micro- and macro-vascular complications of diabetes mellitus

Vascular complications are a leading cause of morbidity and mortality in both men and women with type 1 (T1DM) or type 2 (T2DM) diabetes mellitus, however the prevalence, progression and pathophysiology of both microvascular (nephropathy, neuropathy and retinopathy) and macrovascular [coronary heart disease (CHD), myocardial infarction, peripheral arterial disease (PAD) and stroke] disease are different in the two sexes. In general, men appear to be at a higher risk for diabetic microvascular complications, while the consequences of macrovascular complications may be greater in women. Interestingly, in the absence of diabetes, women have a far lower risk of either micro- or macro-vascular disease compared with men for much of their lifespan. Thus, the presence of diabetes confers greater risk for vascular complications in women compared with men and some of the potential reasons, including contribution of sex hormones and sex-specific risk factors are discussed in this review. There is a growing body of evidence that sex hormones play an important role in the regulation of cardiovascular function. While estrogens are generally considered to be cardioprotective and androgens detrimental to cardiovascular health, recent findings challenge these assumptions and demonstrate diversity and complexity of sex hormone action on target tissues, especially in the setting of diabetes. While some progress has been made toward understanding the underlying mechanisms of sex differences in the pathophysiology of diabetic vascular complications, many questions and controversies remain. Future research leading to understanding of these mechanisms may contribute to personalized- and sex-specific treatment for diabetic micro- and macro-vascular disease.

Ethnic differences in the prevalence of diabetic retinopathy in persons with diabetes when first presenting at a diabetes clinic in South Africa

OBJECTIVE

To describe the prevalence and associated risk factors for diabetic retinopathy (DR) within a multiethnic population at presentation to a diabetes clinic in South Africa.

RESEARCH DESIGN AND METHODS

Retinal photography was conducted using a nonmydriatic digital camera without mydriasis and graded by one of three senior graders. Logistic regression analyses were used to assess the association between any DR, referable DR, and clinical risk factors.

RESULTS

A total of 1,537 persons with type 1 and 3,978 with type 2 diabetes were included. Prevalence of any DR in type 1 diabetes was 35.2% (background DR 26% and referable DR 9.2%) and in type 2 diabetes was 20.5% (14.1 and 6.4%, respectively). In type 1 diabetes, there was an increased risk of any DR in Asian Indians, whereas the risk of referable DR was increased for indigenous Africans compared with Caucasians. In type 2 diabetes, the risk was increased for all non-Caucasians compared with Caucasians. Longer duration of diabetes and elevated HbA(1c) were independently associated with any and referable DR in both type 1 and type 2 diabetes, with the addition of hypertension and smoking in type 1 diabetes when adjusted for age at diagnosis of diabetes, sex, and ethnicity.

CONCLUSIONS

The prevalence of DR in this population from South Africa was similar to that reported globally; however, ethnic differences were observed. Increasing duration of diabetes and poor glycemic control were the strongest risk factors associated with any and referable DR in both type 1 and type 2 diabetes.

Prevalence of diabetic retinopathy in various ethnic groups: a worldwide perspective

The alarming rise in diabetes prevalence is a global public health and economic problem. Diabetic retinopathy is the most common complication of diabetes and the leading cause of blindness among working-age populations in the Western world. Screening and prompt treatment of diabetic retinopathy are not top priorities in many regions of the world, because the impacts of other causes of preventable blindness remain an issue. Ethnicity is a complex, independent risk factor for diabetic retinopathy. Observations from white populations cannot be extrapolated fully to other ethnic groups. The prevalence of diabetic retinopathy, sight-threatening diabetic retinopathy, and clinically significant macular edema are higher in people of South Asian, African, Latin American, and indigenous tribal descent compared to the white population. Although all ethnic groups are susceptible to the established risk factors of diabetic retinopathy-such as length of exposure and severity of hyperglycemia, hypertension, and hyperlipidemia-ethnic-specific risk factors also may influence these rates. Such risk factors may include differential susceptibility to conventional risk factors, insulin resistance, differences in anthropometric measurements, truncal obesity, urbanization, variations in access to healthcare systems, genetic susceptibility, and epigenetics. The rates of nonproliferative diabetic retinopathy appear to be declining in the United States, supporting the observation that better medical management of diabetes and prompt treatment of sight-threatening diabetic retinopathy substantially improve the long-term diabetic retinopathy incidence; studies from other parts of the world are limited and do not mirror this finding, however. We examine the ethnicity and region-based prevalence of diabetic retinopathy around the world and highlight the need to reinforce ethnicity-based screening and treatment thresholds in diabetic retinopathy.

Smoking habits and prevalence of clinical diabetic microangiopathy in insulin-dependent diabetics

All patients having insulin-dependent diabetes with onset before 30 years of age and a duration of disease of 12-40 years who visited a diabetes centre within one year were registered. 97% (n = 668) answered a WHO questionnaire on cigarette smoking. The smoking habits were compared to the frequency of proliferative retinopathy and/or diabetic nephropathy (persistent proteinuria). The prevalence of diabetic nephropathy was significantly higher among heavy smokers (greater than 10 cigarettes a day for more than one year) than among non-heavy smokers, 19.2% versus 12.1% (p less than 0.02). An increasing frequency of nephropathy was found with increasing cigarette consumption (p less than 0.01). No difference in the prevalence of proliferative retinopathy was found between smokers and non-smokers. It is concluded that cigarette smoking is a risk factor for the development of nephropathy in insulin-dependent diabetics.

Smoking and diabetic nephropathy

Forty-seven patients with insulin-dependent diabetes (IDDM) and diabetic nephropathy and 47 controls with IDDM without diabetic nephropathy were interviewed about their previous and current smoking habits. The patients in the two groups were matched according to sex, age, age at onset, and duration of diabetes. All patients in the nephropathy group had proteinuria and decreased glomerular filtration. None in the control group had ever had proteinuria as tested by dip stick. The total amount of smoking until date of interview was estimated for each individual and presented as an index. The patients with nephropathy had a significantly higher smoking index than the controls. In the nephropathy group there were also more numerous current smokers, more heavy smokers and fewer individuals who had never smoked than in the control group. The link between diabetic renal microangiopathy and smoking may be through mechanisms such as increased platelet aggregation, accentuated tissue hypoxia and hemodynamic or metabolic effects of repeated noradrenaline release.

Plasma lipids and plasma lipoproteins in diabetics with and without proliferative retinopathy

The single most important factor related to the development of diabetic retinopathy is the duration of diabetes. Little is known about the underlying mechanisms, but many factors have been suggested to be involved, among them derangements in plasma lipids and plasma lipoproteins. In the present study we examined the relation between plasma lipids, plasma lipoproteins, and the duration of diabetes in Type I diabetics with and without proliferative retinopathy. The duration of diabetes in the two groups was 12.2 +/- 2.8 and 21.5 +/- 9.0 years, respectively (mean +/- SD; p less than 0.01). Except for moderately low HDL levels, plasma lipid and lipoprotein concentrations were normal in both groups of patients. The levels of lipids and lipoproteins did not correlate with the duration of diabetes. Furthermore, no differences were seen between patients with and without proliferative retinopathy. Thus, the present study does not indicate that plasma lipids and plasma lipoproteins play any major role in the development of diabetic proliferative retinopathy.

Complications of diabetes mellitus in childhood

Complications of diabetes include retinopathy, nephropathy, neuropathy, macrovascular disease, and associated autoimmune diseases. Clinical manifestations of complications uncommonly present in childhood and adolescence. Screening during the early years can identify subclinical disease and it offers an opportunity for early intervention. The Diabetes and Complications Control Trial has provided evidence for the long-term benefits of good glycemic control in preventing and delaying the onset of microvascular complications. Complications begin to manifest during adolescence, during which time all efforts should be made to educate and support young persons in achieving optimal diabetes control.

Incidence of diabetic retinopathy in the Barbados Eye Studies

PURPOSE

To examine the 4-year incidence and risk factors for diabetic retinopathy (DR) among black participants with diabetes in the Barbados Eye Studies (BES).

DESIGN

Population-based incidence study.

SETTING AND PARTICIPANTS

Four hundred ten persons with diabetes mellitus (DM) from the BES cohort, which was based on a simple random sample of Barbadians, 40 to 84 years of age at baseline.

MAIN OUTCOME MEASURES

Development of DR, assessed by independent gradings of 30 degrees color stereo fundus photographs of the disc and macula. Associations were evaluated by logistic regression analyses.

RESULTS

After 4 years, DR developed in 92 of 306 (30.1%; 95% confidence interval, 25.0%, 35.5%) persons unaffected at baseline. The incidence of DR was 31.9% in those with known DM at baseline and 20.9% in newly diagnosed DM. Clinically significant macular edema developed in 16 (4.5%) of 353 individuals at risk. Seven (6.9%) of the 101 persons with minimum or moderate DR at baseline progressed to proliferative DR. Age-specific incidence declined from 36.2% at age 40 to 49 years to 28.8% and 24.2% over the subsequent two decades, increasing to 38.2% among those >/=70 years. Risk factors for DR were increased systolic blood pressure (relative risk [RR], 1.16 [1.03, 1.31]/10 mmHg increase); use of oral hypoglycemics (RR, 2.4 [1.3, 4.2]); and use of insulin (RR, 6.1 [1.7, 22.1]) (vs. no treatment or diet only); and elevated glycated hemoglobin (GHb; RR, 6.4 [2.5, 16.0]); GHb >11.5% vs. GHb </=8%).

CONCLUSIONS

High rates of incident DR were evident in the black BES population, also known to have high rates of DM. Prevention of visual loss caused by DR in this population has high priority, including optimal glycemic and blood pressure control.

Plasma brain natriuretic peptide levels in normotensive Type 2 diabetic patients without cardiac disease and macroalbuminuria

To clarify the relationship of the plasma brain natriuretic peptide (BNP) levels to diabetic complications, we studied plasma BNP levels in 100 normotensive diabetic patients without clinical cardiac disease and macroalbuminuria. The values of plasma BNP levels were not significantly different between patients with microalbuminuria and those with normoalbuminuria (12.2 +/- 2.0 vs. 12.3 +/- 1.3 pg/ml, means +/- S.E.M.), and neither were the BNP levels of patients with and without retinopathy significantly different (15.7 +/- 3.4 vs. 11.4 +/- 1.0 pg/ml). BNP levels of the subjects with cerebral vascular disease (CVD) were not statistically different from those of subjects without CVD (17.5 +/- 5.5 vs. 11.7 +/- 1.0 pg/ml), although mean BNP value of subjects with CVD was higher than that of subjects without it. With regard to peripheral vascular disease (PVD), BNP levels of the subjects with PVD were not statistically different from those of subjects without PVD (13.5 +/- 2.3 vs. 12.1 +/- 1.2 pg/ml). We also studied radial arterial oxygen tension of 45 patients and compared these levels between those with and without diabetic complications. However, we could not find statistical differences between them. In conclusion, our study suggests that BNP and arterial oxygen tension levels will not be affected by retinopathy, microalbuminuria, CVD, and PVD in normotensive diabetic patients without clinical cardiac disease and macroalbuminuria. Therefore, when normotensive diabetic patients without macroalbuminuria show increased plasma level of BNP, we should examine their cardiac function in detail, considering subclinical cardiac disease.

Relationship of abdominal fat with metabolic disorders in diabetes mellitus patients

In this study, we examined the relationships of the fat distribution with the clinical parameters, microangiopathy, and coagulation disorders in Japanese diabetic patients, distinguishing between males and females. To investigate these relationships, the clinical parameters of the patients were compared with the total abdominal fat area (TFA), visceral fat area (VFA), subcutaneous fat area (SFA), BMI, and percent body fat. In addition, microangiopathies and coagulation disorders of the patients were also compared with the fat distribution. In the male patients, the insulin level, triglyceride (TG) level, and diastolic blood pressure significantly correlated with both VFA and SFA. The HDL cholesterol (HDL-Chol) level and systolic blood pressure also significantly correlated with VFA, but not with SFA. In the female patients, the insulin level, TG level, HDL-Chol level and systolic blood pressure significantly correlated with VFA. On the other hand, only the systolic and diastolic blood pressures significantly correlated with SFA. The fibrinogen and thrombin-antithrombin III complex (TAT) levels significantly correlated with VFA only in the female patients. The male patients with macroalbuminuria had significantly larger VFA than those with microalbuminuria or normoalbuminuria. However, SFA had no relation with the urinary albumin excretion rate. The multiple regression analysis showed that VFA was an independent variable associated with diabetic nephropathy in the male patients. In conclusion, VFA plays more important role than SFA in the metabolic disorders and diabetic nephropathy in the Japanese diabetic patients. In the female diabetic patients, VFA may be associated with disorders of coagulation and fibrinolysis.

A nonlinear effect of hyperglycemia and current cigarette smoking are major determinants of the onset of microalbuminuria in type 1 diabetes

Cigarette smoking and poor glycemic control are risk factors for diabetic nephropathy in type 1 diabetes. However, the specifics of the relation of these risk factors to the onset of this complication have not been elucidated. To investigate these issues, we followed for 4 years 943 Joslin Clinic patients aged 15-44 years with type 1 diabetes who had normoalbuminuria during the 2-year baseline period. Microalbuminuria developed in 109 of the 943 individuals, giving an incidence rate of 3.3/100 person-years. The risk of onset of microalbuminuria was predicted somewhat more precisely by the measurements during the 1st and 2nd years preceding onset than by all the measurements during the longer (4-year) interval, suggesting attenuation of the impact of past hyperglycemia over time. Point estimates of the incidence rate (per 100 person-years) according to quartiles of HbA(1c) during the 1st and 2nd years preceding the outcome were 1.3 in the 1st, 1.5 in the 2nd, 3.1 in the 3rd, and 6.9 in the 4th (P = 1.3 x 10(-9)). Point estimates of the incidence rate (per 100 person-years) according to smoking status were 7.9 for current smokers, 1.8 for past smokers, and 2.2 for those who had never smoked (P = 2.0 x 10(-7)). In a multiple logistic model, the independent effects of HbA(1c) level and cigarette smoking remained highly significant, but their magnitudes were reduced. Using the same covariates in a generalized additive model, we examined the shape of the relationship between HbA(1c) and onset of microalbuminuria and found significant nonlinearity in the logarithm of odds scale (P = 0.04). The slope was steeper with HbA(1c) >8% than <8%. Furthermore, the change in the slope was magnified among current smokers. In conclusion, patients with type 1 diabetes who smoke and have an HbA(1c) >8% have the highest risk of onset of microalbuminuria.

Elevation of fibrinogen and thrombin-antithrombin III complex levels of type 2 diabetes mellitus patients with retinopathy and nephropathy

Diabetes is associated with a hypercoagulable state. Blood hypercoagulability may accelerate atherosclerosis and the diabetic microvascular complications. Thrombin-antithrombin III complex (TAT) and fibrinogen levels are parameters of coagulation and fibrinolysis. In the present study, we examined the risk factors for the diabetic microangiopathy including TAT and fibrinogen levels. To investigate the relationship between the clinical parameters and microangiopathy in type 2 diabetic patients, the clinical parameters of subjects with microangiopathy were compared with those of subjects without microangiopathy. The clinical parameters were as follows: age at examination, duration of diabetes, fasting plasma glucose (FPG) level, HbA(1C) level, insulin level, TAT level, fibrinogen level, lipoprotein (a) (Lp(a)) level, total cholesterol level, triglyceride level, HDL cholesterol level and existence of hypertension. The plasma TAT and fibrinogen levels were significantly higher in patients with retinopathy or nephropathy than in patients without these complications. Moreover, fibrinogen levels of patients with microalbuminuria or background retinopathy were significantly higher than those of patients with normoalbuminuria or no retinopathy. The duration of diabetes was significantly longer in patients with any microangiopathy than in patients without it. Multiple regression analyses showed that duration and fibrinogen level were independent factors associated with the existence of retinopathy or nephropathy. Our data show that the disorder of coagulation and fibrinolysis is significantly associated with diabetic retinopathy and nephropathy and exists at the early stage of microangiopathy.

The pattern of diabetic nephropathy among Saudi patients with noninsulin-dependent diabetes mellitus

There were no studies on the different stages of diabetic nephropathy in Saudi Arabia, particularly the earliest stages. We have therefore investigated the frequency of occurrence of varying degrees of proteinuria including microalbuminuria in noninsulin-dependent diabetes mellitus (NIDDM) Saudi patients as well as the correlation of varying degrees of proteinuria with other diabetic complications and risk factors. One hundred and twenty-five NIDDM patients were studied. Fifty-seven were males and 68 were females. Their mean age was 49.8 +/- 10 years with a mean duration of diabetes of 9.48 +/- 6 years. The mean of HbA1c was 10.3 +/- 2.6%, serum creatinine was 76.7 +/- 23 mmol/L, creatinine clearance 94.3 mL/min, glomerular filtration rate 129.7 +/- 44 and effective renal plasma flow was 496.5 +/- 153. The pattern of proteinuria group was as follows: nephrotic range proteinuria 5.6%, clinical proteinuria 30.4%, microalbuminuria 16.8%. Hypertension and retinopathy were present in 36.8% and 37% of the patients respectively. A significant correlation was found between the presence of hypertension, duration of diabetes and development of diabetic nephropathy. Similarly, a significant correlation was found between retinopathy and the degree of proteinuria. In conclusion, the pattern of diabetic nephropathy in the Saudi NIDDM patients is similar to that in the Western world. Hypertension and duration of diabetes mellitus are important risk factors in the development of diabetic nephropathy. There is a good correlation between retinopathy and the degree of proteinuria.

Cigarette smoking and diabetes: an update

The article provides an overview of recent scientific information on the role of cigarette smoking in the prognosis of diabetes. Data sources included an English-language MEDLINE search for 1989 through 6/1993, supplemented by manual search of bibliographies of pertinent articles. Only studies of humans were considered. Cigarette smoking is related to the development and progression of diabetic nephropathy. Therefore, smoking status has to be taken into account in clinical studies on the course of nephropathy. The association between smoking and retinopathy is less consistent. Evidence is accumulating that cigarette smoking influences insulin action. Several large prospective cohort studies have shown that the relative risk for all-cause mortality is about twice as high for smoking compared to non-smoking diabetic patients. Strong associations are consistently found between cigarette-pack years and complications. It has been calculated that the theoretical benefit of stopping smoking is the most (cost-)effective risk factor intervention for diabetic patients. However, available programmes to help diabetic patients to stop smoking are unsuccessful.

Effects of combined insulin and sorbinil treatment on diabetes-induced vascular dysfunction in rats

These experiments were undertaken to assess the effects of combined treatment with insulin (designed to partially restore metabolic control) and sorbinil (an aldose reductase inhibitor [ARI]) versus the effects of sorbinil alone or of two insulin regimens providing different degrees of glycemic control on diabetes-induced metabolic derangements and vascular function. Streptozocin-diabetic rats were divided into the following five groups: (1) untreated (D); (2) treated with approximately 1 U NPH insulin/100 g body weight/d administered in one subcutaneous (SC) injection (DI-1); (3) treated with the same total daily dose of insulin administered in two SC injections (DI-2); (4) treated with approximately 0.2 mmol sorbinil in the diet/kg body weight/d (DS); and (5) treated with once-daily insulin plus sorbinil (DSI-1). Two groups of nondiabetic rats, untreated (C) and sorbinil-treated (CS), served as controls. Metabolic parameters were unaffected by sorbinil treatment in controls and diabetics, whereas insulin administration in the diabetics virtually normalized body growth, food consumption, urine volume, and plasma glucose levels, and markedly decreased hemoglobin A1 (HbA1) levels. Two daily injections were more effective than one in improving metabolic control as measured by HbA1 levels. Regional vascular 131I-albumin permeation was increased about twofold to threefold by diabetes in ocular tissues, sciatic nerve, aorta, diaphragm, and new granulation tissue; it was decreased (but not normalized) by insulin treatment in accordance with improved metabolic control, and was completely normalized by sorbinil. 131I-albumin kidney clearance, as well as urinary albumin and IgG excretion, were markedly increased in diabetic rats and were significantly decreased but not completely normalized by sorbinil and by twice-daily insulin treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

The prevalence of diabetic retinopathy and maculopathy and their risk factors in the non-insulin-treated diabetic patients of an English town

A total population study of the ocular status of all known non-insulin-treated diabetic patients resident in the English town of Melton Mowbray has been conducted. The population prevalence of non-insulin-treated diabetes in the town was 6.7/1000. There were 215 patients in the target population, with 65% of the resident survivors participating in the study. Further data on ocular status were gathered from hospital records, bringing the total percentage for whom some information on ocular status was available to 74%. Corrected Snellen acuity was 6/12 or better in 76% of patients and the over-all prevalence rate for any diabetic retinopathy was 52%, for proliferative retinopathy was 4%, and for maculopathy requiring treatment was 10%. In a multivariate analysis, risk factors for retinopathy and/or maculopathy included longer diabetic duration, female sex, higher blood pressure, the use of anti-hypertensive drugs and cigarette smoking.

Diabetes mellitus and operated peptic ulcer disease

There is some evidence of an antagonism between peptic ulcer and diabetes mellitus. This antagonism is possibly related to anomalous insulin metabolism in duodenal ulcer patients. To evaluate this issue, 471 Rochester, Minnesota residents who had surgery for peptic ulcer were examined and then followed for up to 34 years. Their experience of diabetes mellitus was compared with that of Rochester residents generally, for whom data on diabetes incidence and prevalence were available. At surgery, the prevalence of diabetes was somewhat increased for gastric and slightly diminished for duodenal ulcer patients. Of the 445 patients who were free of diabetes at surgery, 27 developed it. By 20 years, the cumulative incidence of diabetes (9.1%) was less than expected (10.3%), but over the 20 years the difference was not significant for either gastric or duodenal ulcer patients. The risk of diabetes was not influenced by age, gender, or smoking status but analysis for relative weight at surgery indicated that obese patients had a 2.6-fold increase in risk of subsequent diabetes, whereas those with less than 1.2 relative weight had reduced risk. Relative weight was the only significant predictor of the time to subsequent diabetes in a proportional hazards regression analysis. The proposition of an antagonism between peptic ulcer and diabetes is not supported by the data.

Prevalences of risk factors and angiopathy in diabetic patients in Uppsala

The prevalences of risk factors and angiopathy were studied in 260 diabetic patients, 100 females and 160 males, 35-54 years old, in Uppsala. The prevalence, in females and males separately, of hypertension (WHO-criteria) was 46-34%, of hypercholesterolaemia (greater than or equal to 6.7 mmol.l-1) 32-29%, and of obesity (relative BMI greater than or equal to 120%) 25-20%. Those smoking greater than 15 cigarettes/day were 11-20%. Mean HbA1 was 10.6-10.5%. The prevalence of angina pectoris was 11-6%, of possible infarction 4-6%, and of major ECG abnormalities 6-4%. Large vessel (cardiovascular) disease was independently related to HbA1 (strongly), hypertension, cholesterol, age and familial NIDDM. The prevalence of severe retinopathy (blindness, new vessels or large hemorrhage) was 0% with 7-13 years of diabetes duration, and 26% with greater than or equal to 14 years of duration. The prevalence of severe proteinuria was 4% with 7-13 years of diabetes duration, and 15% with greater than or equal to 14 years of duration. Small vessel (retinopathy and nephropathy) disease was independently related to diabetes duration (strongly), HbA1 and hypertension. The data were discussed related to data from the London, Berlin and Tokyo centres of the WHO Multinational Study of Vascular Disease in Diabetics, using the same study protocol in the present study.

Glucose intolerance and diabetic complications among Japanese-American women

The prevalence of glucose intolerance and diabetic complications was determined in second-generation Japanese-American (Nisei) women and compared to previously obtained results in Nisei men. A volunteer study sample of 191 Nisei women 45-74 years old was enrolled from a study population of 1489 Nisei women born 1913-1942, raised and educated in the U.S., and residing in King County, Washington. The enrolled sample included 72 with normal glucose tolerance, 67 with impaired glucose tolerance (IGT), and 52 with non-insulin-dependent diabetes. A random sample was also drawn from the study population to form a reference sample of 157 women. Based upon observations in the reference and enrolled samples, an estimated 16% of Nisei women in the study population have diabetes and 40% IGT. These rates compare to 20% diabetes and 36% IGT previously estimated for Nisei men 45-74 years old. The prevalence of cardiovascular disease (hypertension, peripheral vascular disease, and/or coronary heart disease) was highest among diabetic women, lowest in those with normal glucose tolerance, and intermediate in women with IGT. In comparison to diabetic men, there was a significantly lower frequency of neuropathy, peripheral vascular disease, and coronary heart disease in diabetic women. However, hypertension occurred equally often in both. Thus Japanese-American men and women 45-74 yr old have a similar prevalence of glucose intolerance, although less severe in women, and complications, except for hypertension, are reduced in women.

The epidemiology and prevalence of diabetic retinopathy in the Veneto region of north east Italy. Veneto Group for Diabetic Retinopathy

The prevalence of diabetic retinopathy and its relationship to a number of risk factors were examined in a population-based study in the Veneto region of North East Italy. Of 1321 diabetic patients selected, 98% attended for examination. Prevalence of diabetic retinopathy was 26.2% (24.4% background and 1.8% proliferative). The prevalence of retinopathy was significantly related (p less than 0.01) to the duration of diabetes (17.3% for less than 5 years; 60.8% for greater than 20 years). Proliferative retinopathy was much more prevalent after 20 years of diabetes. After 10 years most proliferative retinopathy was found in Type 1 diabetic patients, but before 10 years from diagnosis it was most prevalent in Type 2 diabetes. The prevalence of retinopathy was significantly related (p less than 0.001) to the type of diabetes and was found predominantly in Type 1 (46.2%) and insulin-treated Type 2 (45.9%) subjects and to a lesser degree in non-insulin-treated patients (24.6%). The prevalence of retinopathy was significantly related to both fasting and post-prandial blood glucose levels (p less than 0.001), blood urea nitrogen (p less than 0.05), and systolic (p less than 0.001) and diastolic (p less than 0.01) blood pressure. No significant differences were found in the prevalence of total or proliferative retinopathy between males and females. No significant relationships were found with family history of diabetes, alcohol intake, smoking habits, cholesterol, triglycerides, and serum uric acid.

A study of patients with diabetes mellitus (type 1) and end-stage renal failure: tobacco usage may increase risk of nephropathy and death

Thirty-four consecutive patients with diabetes mellitus as a plausible cause of end-stage renal failure were investigated with regard to outcome and tobacco consumption. The mean duration of diabetes was 25.5 years. Thirty-one of the patients had used tobacco regularly for at least 5 years. For 28 patients it was possible to calculate the intake of tobacco as the daily mean and the total consumption (expressed as pack years). The time period (in years) between initiation of tobacco usage and onset of persistent proteinuria, as an early indicator of diabetic nephropathy, was shorter if the daily consumption of tobacco was higher (P less than 0.01) and the total consumption (pack years) in these patients was lower (P less than 0.05). There was an increased risk of early death (P less than 0.01) in patients who were currently smokers when they were uraemic (predialysis), on dialysis or had kidney grafts, compared to those who had never used tobacco or who were ex-smokers. In conclusion, it appears to be important for insulin-dependent diabetic patients to avoid tobacco usage and for current smokers to give up the habit in order to reduce the risk of diabetic nephropathy and early death.

Clinical characteristics associated with microalbuminuria in an adult diabetic population

A study was conducted to identify clinical characteristics which might distinguish individuals at risk for diabetic nephropathy. A cross-sectional survey measuring microalbuminuria in a population of 140 diabetic adults was performed and several clinical parameters among subgroups with different clinical types of diabetes, based upon age of onset and insulin treatment, were examined. In 67 insulin-treated patients with onset of diabetes at or after the age of 30 who had elevated albumin excretion rates, significantly greater duration of diabetes, age, blood pressure, serum creatinine, body mass index, and serum triglycerides were found. In this group of maturity onset insulin-treated diabetic patients, there was a significantly smaller proportion of smokers in the microalbuminuria group than in the group with normal excretion. No such distinctions were seen in 58 maturity onset patients with and without microalbuminuria who were not receiving insulin. In 15 insulin dependent patients with onset in early adulthood, only age and duration distinguished those with, or without, microalbuminuria. Analysis of microalbuminuria, taking into account diabetes therapy and other clinical and demographic data, may provide clues to the pathophysiology of renal disease in diabetes mellitus.

Smoking and diabetes

The frequency of smoking in diabetic patients is not appreciably different from that in the general population. As in non-diabetic subjects, smoking is a major cardiovascular risk factor in diabetic patients. For young diabetic patients, smoking has been identified as a risk for macroproteinuric nephropathy. In respect of retinopathy, study results are more controversial. Recent studies also suggest smoking as a risk indicator for extra-articular connective tissue changes and neuropathy. Patients who already present with vascular complications, pregnant women, and women who use oral contraceptive drugs appear to run a particularly high risk by smoking. Stopping smoking reduces the risk of vascular morbidity and mortality in non-diabetic subjects. Although no comparable studies are available for diabetic populations, it should be assumed that the beneficial effects of stopping smoking are applicable to diabetic patients as well. Programmes to encourage diabetic patients to stop smoking are scarce and have not been successful.

The epidemiology of diabetic nephropathy

Many areas of information in the epidemiology of diabetic nephropathy are lacking, but multiple studies designed specifically to answer these questions are currently being conducted. In the next 5-10 years, our current understanding of the epidemiology of diabetic nephropathy may either be confirmed or discredited. In the meantime, clinicians should use the data available to make decisions about treatment and should focus on the modifiable factors of glucose and blood pressure control in both IDDM and NIDDM, especially in patients with low-level albuminuria or clinical proteinuria.

Nephropathy in non-insulin-dependent diabetes mellitus

End-stage renal disease develops in about 5 percent of patients with non-insulin-dependent diabetes mellitus (NIDDM). The large majority of diabetic patients have this form of the disease. Thus, end-stage renal disease is an important clinical problem in patients with NIDDM. Moreover, hypertension and its macrovascular sequelae are significant problems in patients with NIDDM and may be linked with renal disease. A review of the problem of nephropathy in NIDDM is attempted, pointing out, where data are available, the clinical and pathophysiologic differences from its presentation in insulin-dependent diabetes. The need for further studies of the impact of renal disease in this maturity onset form of diabetes is emphasized.

The prevalence of proteinuria detected by Albustix in a defined diabetic population

All the known diabetic patients (917) from a defined population (90,660) were called for review by a single observer. A total of 842 (92%) attended and proteinuria, identified using Albustix (0.3 g/l or more), was found in 57 cases (6.8%), but in 9 this was in association with a urinary tract infection. Diastolic blood pressure, an ulcerated or amputated lower limb, and smoking category were found to be the only significant predictors of proteinuria after a multiple logistic regression analysis. A serum creatinine greater than 150 mumol/l was found in 29 (3.8%) of the 768 diabetics in whom it was measured. However, proteinuria was only present in 7 of the diabetics with impaired renal function. In those aged less than 65 years, the prevalence of proteinuria with impaired renal function was 0.75%.

Proteinuria and blood glucose levels in a population with diabetic retinopathy

In a population-based study of all insulin-treated diabetic patients on the Swedish island of Gotland, we compared the prevalence and severity of retinopathy with those of nephropathy as measured by proteinuria and serum creatinine levels. Of 365 diabetic patients, 66 (18%) had proteinuria. Of these 66, 39 (59%) had retinopathy. Proteinuria and serum creatinine correlated with increasing severity of retinopathy (P less than .001). Of 47 patients with proliferative retinopathy, 19 (40%) had proteinuria. Of 124 patients with retinopathy of other grades of severity, 20 (16%) had proteinuria. Visual acuity in the best eye was negatively correlated to proteinuria, which was present in 17 of 203 (8.4%) patients with a visual acuity of 20/20, compared with eight of 15 (53%) of those with a visual acuity of 20/200 or less. Blood glucose, determined two hours postprandially, was satisfactory (less than 10 mmol/l) in 162 patients (44%), unsatisfactory (10 to 14 mmol/l) in 89 (24%), and poorly regulated (greater than 14 mmol/l) in 114 (31%). Increasing mean blood glucose correlated to retinopathy (P less than .05).

Lack of relationship between beta-hexosaminidase activity and retinopathy in insulin dependent diabetics

Beta-hexosaminidase activity in plasma and urine was measured and compared in insulin dependent diabetics (IDDM) with and without proliferative retinopathy. No difference in the activity of beta-hexosaminidase was found between the two groups indicating that this enzyme is not involved in the development of diabetic microangiopathy.

Platelet aggregation in type I diabetics with and without proliferative retinopathy

The cause of retinopathy in diabetes mellitus is unknown. Among factors suggested to be involved in the development of retinopathy is altered platelet function. In the present study, platelet aggregation was measured in vitro after stimulation with adenosine diphosphate (ADP) and collagen in patients with and without proliferative retinopathy. The results show that patients with proliferative retinopathy have an increased platelet aggregation in vitro after stimulation with collagen and ADP. However, the increased platelet aggregation was also found to be correlated to the duration of diabetes. Thus, the present study does not support the opinion that abnormal platelet function can be regarded as a primary cause of diabetic retinopathy. Increased platelet aggregation seems to be coupled to the duration of diabetes and to still unknown factors developing with prolonged duration of the disease.

Genetic and metabolic risk factors for the development of late complications in type I (insulin-dependent) diabetes

The genetic background seems to be involved in the development of type I diabetes and it might also be involved in the development of diabetic complications, but studies carried out so far have yielded conflicting results. The aim of this study was to evaluate the influence of some genetic markers and metabolic factors in the development of late diabetic complications. One hundred and twenty-seven patients (69 males, 58 females) with type I diabetes were evaluated for ABO and Rh blood groups, chlorpropamide alcohol flush (CPAF) and acetylator phenotype (AP) as well as for life-habits (smoking, alcohol use, diet and drug compliance), metabolic indexes (M-value, HbA1, cholesterol and triglyceride levels) and late complications of diabetes [coronary heart disease (CHD), arterial hypertension (AH), retinopathy and nephropathy]. Diabetic patients were more frequently fast acetylators and CPAF positive than controls and CPAF was more frequent among females than among males. None of the genetic markers used in this study appeared as a risk factor for the development of diabetic complications. At multiple logistic analysis different risk factors appeared for each microangiopathic complication. For retinopathy: female sex, duration of disease and triglyceride levels; for nephropathy: male sex, cholesterol levels and hypertension. These risk factors have already been recognized in previous studies, while the genetic markers evaluated in our study do not identify a greater or smaller risk for the development of late complications.

Residual B-cell function in insulin-dependent (type I) diabetics with and without retinopathy

In order to evaluate if residual B-cell function is a protecting factor against the development of diabetic retinopathy in type I diabetics we measured C-peptide levels before and after glucagon stimulation (1 mg i.v.) in 74 type I diabetics. In all patients retinopathy was assessed by fluorescein angiography and retinal lesions were classified as: grade 0, normal; grade 1, background retinopathy; grade 2, proliferative retinopathy. We then correlated the degree of retinopathy to sex, age, duration of diabetes, smoking, percentage of ideal body weight, systolic and diastolic blood pressure, serum cholesterol, triglycerides, creatinine and C-peptide by means of multiple linear regression analysis. Twenty-three out of 74 type I diabetics had retinopathy. In all 7 subjects with proliferative retinopathy duration of diabetes exceeded 10 years. There was significant correlation between retinopathy and duration of diabetes (r = 0.373, p less than 0.001). No correlation was found between retinopathy and all the other variables, in particular between retinopathy and basal C-peptide or C-peptide increment (delta). An inverse correlation was found between the increment of C-peptide and duration of diabetes (r = -0.404, p less than 0.01). Our data show that residual B-cell function cannot be considered a protecting factor against the development of diabetic retinopathy.

Prevalence of small vessel and large vessel disease in diabetic patients from 14 centres. The World Health Organisation Multinational Study of Vascular Disease in Diabetics. Diabetes Drafting Group

A total of 6695 diabetic men and women, aged 35 to 54 years, from 14 centres and representing 13 national groups, participated in a vascular disease prevalence survey. A random sample was drawn after stratification of each centre's diabetic base population by sex, duration of diabetes and age. A common agreed protocol, standardized examination procedures, and centralized laboratory methods were used in the investigation. Within the age range examined there was considerable variation between centres in a number of variables, including degree of obesity (measured as Body Mass Index (BMI)), proportion treated with insulin and proportion of cigarette smokers. The latter also showed considerable sex differences within centres. Subjects with age at onset below 25 years were notably few in Hong Kong, Tokyo and Oklahoma. There was also considerable variation in the apparent prevalence of both large- and small-vessel (macrovascular and microvascular) disease between centres. In pooled data, measures of large-vessel disease were significantly and independently associated with age, blood pressure and BMI in both sexes, and with diabetes duration and plasma cholesterol in men only. Within-centre analyses showed blood pressure to be the most consistently associated variable in both sexes. In pooled data, small-vessel disease of the eye was significantly and independently associated with diabetes duration, blood pressure, BMI and type of treatment in both sexes. In within-centre analyses, diabetes duration was the most consistently associated variable, followed by blood pressure. Proteinuria as an index of small-vessel disease of the kidney was, in pooled data, significantly and independently correlated with diabetes duration, blood pressure and plasma cholesterol in both sexes. In within-centre analyses, blood pressure was the most consistently associated variable, with diabetes duration and plasma cholesterol equal second - significant in 12 of the 28 centre/sex groups. Heterogeneity of large-vessel disease prevalence in diabetic subjects is confirmed by this study, and the possibility of heterogeneity in small-vessel disease prevalence and severity is suggested.

Determinants of patient compliance, control, presence of complications, and handicap in non-insulin-dependent diabetes

Factors affecting patient compliance with diet and medication, clinical control, complications, and handicap were studied in 114 subjects with non-insulin-dependent diabetes mellitus who were attending a hospital diabetic clinic. Compliance with diet and hypoglycemic medication was correlated. The perceived importance, and the ease of compliance were the principal correlates of patient compliance. Factors independently related to diabetic control were compliance with diet, and the quality of the patient's diet. Diabetes which was poorly controlled, and which was of several-years' standing, was more likely to involve complications. Both poor control and the presence of complications contributed to handicap. Increased dietary education and counselling, with emphasis placed on the importance and benefits of compliance with prescribed diets, may improve control, decrease the incidence of complications, and ultimately minimise handicap due to diabetes in non-insulin-dependent patients.

[Vascular diseases in 534 Swiss diabetics within the scope of a multinational study]

In Switzerland 278 diabetic men and 256 women in the age group 35 to 54 were examined for the presence of angiopathic lesions, according to a standardized protocol of a multinational study comprising 6,695 diabetics from 14 countries. The diabetics were distributed according to sex, age, and duration of the disease into groups of equal size. Macro-angiopathy, as the sum of coronary heart disease, stroke, and vascular disease of the legs was found in 28% of men and in 29% of women in the Swiss group. The prevalence of myocardial infarction alone was 6.8% in men and 5.5% in women. These rates did not differ from those found in the other national groups. Micro-angiopathy was found in the form of retinopathy in 35% and as nephropathy in 32% of the Swiss diabetics. These rates were not different from those of all groups. Severe retinopathy was found more frequently in Swiss diabetics than in the whole study. Micro-angiopathy was strongly related to duration, hypertension, and type of treatment in all centres. Japanese diabetics showed a higher frequency of micro-angiopathy, although macrovascular disease was found at a low rate. Systolic blood pressure (BP) in the Swiss diabetics did not differ from the results of the whole group. In 14% of the Swiss diabetic men and in 18% of the women, systolic BP was over 160 mmHg. These rates were remarkably higher than in an age- and sex-matched sample of a randomly selected sample of a Swiss population (3.2% in men, 2.4% in women). Cholesterol was high in the Swiss diabetic groups, whereas body mass index was in the intermediate range. Of the Swiss diabetic men 38% smoked regularly. The frequency of coronary heart disease in Swiss men and women was similar. This is different from the lower rate usually found in non-diabetic women. Age, and not duration of the disease was the most important factor relating to macro-angiopathy. The different rates of macro- and microvascular complications in various populations, selected according to the same protocol, suggests that the risk factors for macrovascular disease differ from those of microvascular complications. Race, nutrition, treatment, exercise, and hypertension may further influence the prevalence of angiopathy in diabetics of same sex, age, and duration of the disease.