Birgitte V. Hansen

Lack of relationship between an insertion/deletion polymorphism in the angiotensin I-converting enzyme gene and diabetic nephropathy and proliferative retinopathy in IDDM patients.

Genotypic abnormalities of the renin-angiotensin system have been suggested as a risk factor for the development of diabetic nephropathy and proliferative retinopathy. We studied the relationship between an insertion(I)/deletion (D) polymorphism in the angiotensin-converting enzyme (ACE) gene in insulin-dependent diabetes mellitus (IDDM) patients with diabetic nephropathy (121 men and 77 women, age 40.9 ± 10 years, diabetes duration 27 ± 8 years) and in IDDM patients with normoalbuminuria (118 men and 74 women, age 42.7 ± 10 years, diabetes duration 26 ± 8 years). A total of 155 patients (40%) had proliferative retinopathy, and 67 patients (17%) had no diabetic retinopathy. There was no difference in genotype distribution between IDDM patients with diabetic nephropathy and those with normoalbuminuria: 63 (32%)/95 (48%)/40 (20%) vs. 67 (35%)/77 (41%)/46 (24%) had DD/ID/II genotypes, respectively. Patients with nephropathy had higher plasma ACE levels (609 [151–1,504] ³g/l) compared with patients with normoalbuminuria (428 [55–1,630] ³g/l) (P < 0.001). Multiple linear regression analysis revealed that the plasma ACE level in patients with nephropathy is partially determined by ACE/ID polymorphism, mean arterial blood pressure, and glomerular filtration rate (r2 = 0.30, P < 0.001). There was no difference in genotype distribution between IDDM patients with proliferative retinopathy and those without diabetic retinopathy: 52 (34%)/74 (48%)/29 (19%) vs. 26 (39%)/25 (37%)/16 (24%) had DD/ID/II genotypes, respectively. There was also no difference in plasma ACE concentration detected among patients with no, simplex, or proliferative retinopathy. We conclude that the ACE/ID polymorphism does not contribute to the genetic susceptibility to diabetic nephropathy and proliferative retinopathy, whereas the raised plasma ACE concentration may play a role in the initiation and progression of diabetic nephropathy in Caucasian IDDM patients.

Insertion/deletion polymorphism in the angiotensin-l-converting enzyme gene is associated with coronary heart disease in IDDM patients with diabetic nephropathy

SummaryInsulin-dependent diabetic (IDDM) patients with diabetic nephropathy have a highly increased morbidity and mortality from coronary heart disease. An insertion (I) /deletion (D) polymorphism in the angiotensin-I-converting enzyme (ACE) gene has been shown to be associated with coronary heart disease. Therefore, we have investigated the role of this ACE/ID polymorphism in 198 IDDM patients with diabetic nephropathy and 190 normoalbuminuric IDDM patients. The prevalence of myocardial infarction and other coronary heart disease was significantly elevated in patients with nephropathy, 19% (38/198) vs 8% (15/190), p < 0.001. In the nephropathic group 12 of 63 (19%), 23 of 95 (24%), and 3 of 40 (7.5 %) patients with the DD, ID and II genotypes, respectively had a history of coronary heart disease, II vs DD and ID, p < 0.05 when compared to nephropathic patients without coronary heart disease. Multiple logistic regression analysis of the risk factors associated with coronary heart disease in univariate analysis revealed that the II genotype acts as an independent protective factor against coronary heart disease, odds ratio II/DD + ID 0.27 (95 % confidence interval 0.07–0.97, p < 0.05). There was no difference in genotype or allele frequency (D/I) between patients with and without nephropathy, 0.56/0.44 in both groups, but plasma ACE concentration was elevated in patients with nephropathy 609 (151–1504) ng/ml as compared to patients with normoalbuminuria, 428 (55–1630) ng/ml, p < 0.001. We suggest that ACE/ID polymorphism may influence the frequency of life-threatening cardiac complications in IDDM patients suffering from diabetic nephropathy, a condition characterized by increased plasma ACE concentration.

Low Birth Weight: A Risk Factor for Development of Diabetic Nephropathy?

It has been demonstrated that intrauterine growth retardation, defined as birth weight below the 10th percentile, gives rise to a reduction in nephron number. Oligonephropathy has been suggested to increase the risk for systemic and glomerular hypertension in adult life as well as enhance risk for expression of renal disease after exposure to potentially injurious renal stimuli. The aimof this study was to determine if low birth weight is a risk factor for development of diabetic nephropathy. In a case-control study, we investigated 184 (110 men) insulin-dependent diabetes mellitus (IDDM) patients with diabetic nephropathy (persistent albuminuria >300 mg/24 h)(age [mean ± SD] 41.0 ± 9.3 years, duration of diabetes 26.9 ± 8.2 years) and 182 (111 men) normoalbuminuric (<30 mg/24 h) IDDM patients (age 42.1 ± 9.8 years, duration of diabetes 25.8 ± 8.6 years). Information about weight at birth was obtained from the midwifes original registrations. In women below the 10th percentile in birth weight (≤2,700 g, n = 16), 75% had nephropathycompared with only 35% among patients whose birth weights were above the 90th percentile (≥4,000 g, n = 17) (P = 0.05). In men below the 10th percentile in birth weight (≤ 2,910 g, n = 22), the prevalence of patients with nephropathy (50%) was similar to the prevalence among patients above the 90th percentile in birth weight (≥4,200 g, n = 24) (54%). Weights at birth (means ± SD) were similar in patients with and without diabetic nephropathy: men, 3,548 ± 554 and 3,555 ± 493 g; women, 3,265 ± 621 and 3,373 ± 577 g, respectively. Adult height was significantly correlated with weight at birth (r = 0.18, P = 0.008 for men; r = 0.28, P < 0.001 for women). Men with diabetic nephropathy were significantly shorter than men with normoalbuminuria (176.9 ± 7.1 vs. 179.4 ± 6.5 cm, P < 0.01). In conclusion, our study supports the hypothesis that genetic predispositionor factors operating in utero or early childhood or both contribute to the development of diabeticnephropathy.

Angiotensinogen Gene Polymorphisms in IDDM Patients With Diabetic Nephropathy

Genotypic abnormalities of the renin-ANG system have been suggested as a risk factor for the development of diabetic nephropathy. Cleavage of angiotensinogen is the rate-limiting step in the activation of the renin-ANG system. The TT genotype of a polymorphism encoding threonine instead of methionine (M235T) has been associated not only with increased plasma angiotensinogen concentration but also with essential hypertension. In addition, a polymorphism in the angiotensinogen gene substituting methionine for threonine (T174M) has been associated with hypertension in nondiabetic populations. We studied the relationship between these polymorphisms in the angiotensinogen gene in IDDM patients with diabetic nephropathy (121 men, 74 women, age 40.9 ± 10 years, diabetes duration 27 ± 8 years). There was no difference in M235T genotype distribution between IDDM patients with diabetic nephropathy and those with normoalbuminuria: 73/97/25 (37/50/13%) vs. 67/95/23 (36/52/12%) had MM/MT/TT genotypes, respectively. No difference in distribution of T174M genotypes between nephropathic and normoalbuminuric IDDM patients was observed either: 148/44/1 (77/23/0.5%) vs. 141/42/2 (76/23/1%) had TT/TM/MM genotypes, respectively. In patients with nephropathy, systolic blood pressure was higher (161 ± 22 mmHg [mean ± SD]) in patients carrying TT genotype of the M235T angiotensinogen polymorphism as compared with patients with MM or MT genotypes (150 ± 23 mmHg; P = 0.03). We conclude that neither the M235T nor the T174M polymorphism in the angiotensinogen gene contributes to genetic susceptibility to diabetic nephropathy in white IDDM patients, whereas the TT genotype of the M235T is associated with elevated blood pressure in patients with diabetic nephropathy.

Fish Oil in Diabetic Nephropathy

OBJECTIVE Recent studies in nondiabetic kidney diseases suggest that dietary supplementation with n-3 polyunsaturated fatty acids (fish oil) may have beneficial effects on albuminuria, kidney function, arterial blood pressure, and dyslipidemia. Therefore, we evaluated the long-term effect of fish oil in diabetic nephropathy. RESEARCH DESIGN AND METHODS A 1-year double-blind randomized controlled study comparing fish oil (4.6 g n-3 fatty acids/day) with placebo (olive oil) was performed in an outpatient clinic in a tertiary referral center. Thirty-six normotensive IDDM patients with diabetic nephropathy were included; 18 were treated with fish oil. Seven patients dropped out (four received fish oil), and results for the remaining 29 are presented. Albuminuria (enzyme immunoassay), glomerular filtration rate (51Cr-labeled EDTA plasma clearance), 24-h ambulatory blood pressure, and lipid profile were determined every 6 months. RESULTS Albuminuria increased by 22% (1–46%) (mean [95% CI]) in the fish oil group vs. 15% (−11–49%) in the placebo group (NS). Glomerular filtration rate decreased from 116 ± 7 to 105 ± 7 ml · min−1 · 1.73 m−2 (mean ± SE) vs. from 108 ± 6 to 103 ± 7, fish oil and placebo, respectively (NS). No significant changes occurred in 24-h ambulatory blood pressure: from 141 ± 4/82 ± 2 mmHg to 142 ± 5/83 ± 2 vs. from 140 ± 4/78 ± 2 to 144 ± 4/80 ± 3, fish oil and placebo, respectively (NS). In the fish oil group, serum triglycerides (median [range]) decreased from 0.97 (0.5–4.0) mmol/l to 0.8 (0.4–3.0) vs. from 1.01 (0.4–2.0) to 1.09 (0.4–2.0) in the placebo group (P < 0.05) and VLDL cholesterol decreased from 0.45 (0.23–1.88) to 0.37 (0.21–1.43) mmol/l vs. from 0.44 (0.21–0.94) to 0.41 (0.17–1.94) (P < 0.05), but total and LDL cholesterol rose in the fish oil compared with the placebo group. CONCLUSIONS Our study does not suggest that fish oil has beneficial effects on albuminuria, kidney function, blood pressure, and dyslipidemia in normotensive IDDM patients suffering from diabetic nephropathy.

Combining insulin with metformin or an insulin secretagogue in non-obese patients with type 2 diabetes: 12 month, randomised, double blind trial

Objectives To study the effect of insulin treatment in combination with metformin or an insulin secretagogue, repaglinide, on glycaemic regulation in non-obese patients with type 2 diabetes. Design Randomised, double blind, double dummy, parallel trial. Setting Secondary care in Denmark between 2003 and 2006. Participants Non-obese patients (BMI ≤27) with preserved beta cell function. Interventions After a four month run-in period with repaglinide plus metformin combination therapy, patients with a glycated haemoglobin (HbA1c) concentration of 6.5% or more were randomised to repaglinide 6 mg or metformin 2000 mg. All patients also received biphasic insulin aspart 70/30 (30% soluble insulin aspart and 70% intermediate acting insulin aspart) 6 units once a day before dinner for 12 months. Insulin dose was adjusted aiming for a fasting plasma glucose concentration of 4.0-6.0 mmol/l. The target of HbA1c concentration was less than 6.5%. Treatment was intensified to two or three insulin injections a day if glycaemic targets were not reached. Main outcome measure HbA1c concentration. Results Of the 459 patients who were eligible, 102 were randomised, and 97 completed the trial. Patients had had type 2 diabetes for approximately 10 years. At the end of treatment, HbA1c concentration was reduced by a similar amount in the two treatment groups (insulin plus metformin: mean (standard deviation) HbA1c 8.15% (1.32) v 6.72% (0.66); insulin plus repaglinide: 8.07% (1.49) v 6.90% (0.68); P=0.177). Total daily insulin dose and risk of hypoglycaemia were also similar in the two treatment groups. Weight gain was less with metformin plus biphasic insulin aspart 70/30 than with repaglinide plus biphasic insulin aspart 70/30 (difference in mean body weight between treatments −2.51 kg, 95% confidence interval −4.07 to −0.95). Conclusions In non-obese patients with type 2 diabetes and poor glycaemic regulation on oral hypoglycaemic agents, overall glycaemic regulation with insulin in combination with metformin was equivalent to that with insulin plus repaglinide. Weight gain seemed less with insulin plus metformin than with insulin plus repaglinide. Trial registration NCT00118963

Polymorphisms in the Interleukin-1 Gene Cluster Do Not Contribute to the Genetic Susceptibility of Diabetic Nephropathy in Caucasian Patients With IDDM

Glomerular basement membrane thickening and increased accumulation of extracellular matrix are predominant features of the expanding mesangium in diabetic glomerulosclerosis (1). Interleukin-1 (IL-1) stimulates mesangial cell proliferation and extracellular matrix production (2). IL-lRa is a natural endogenous inhibitor that binds to the IL-1 receptor (IL-1RI) with equal affinity as IL-1, but without activating the cell. In streptozotocin-induced diabetic rats, shear-stress induced by glomerular hyperperfusion affects the mesangial cell phenotype, manifesting in increased transcription, translation, and secretion of IL-ip (3). Therefore, the genes in the IL-1 gene cluster can be considered as candidate genes for diabetic nephropathy. Polymorphisms in the genes coding for IL-ip (4) and IL-lRa (5,6) are involved in regulation of the function of IL-1. Recently, a study of a small and heterogeneous group of IDDM and NIDDM patients suggested the penta-allelic insertion polymorphism in the gene coding for IL-lRa as a risk marker for diabetic nephropathy (7). We studied the relationship among polymorphisms in the genes coding for IL-1 (3, IL-lRa, and IL-1RI (the IL-1 gene cluster) in IDDM patients with and without diabetic nephropathy. The patients participating in this study have been described in detail previously (8). Lymphocytes were isolated from peripheral blood, and DNA was prepared by standard techniques. A Taq I restriction fragment-length polymorphism of the IL-1B locus comprising polymorphic fragments of 13.4 kb (B*l allele) and 9.4 kb (B*2 allele) was identified by polymerase chain reaction (PCR) (4). An 86-bp tandem repeat of the second intron of the IL-lRa gene was characterized by PCR amplification and alleles termed Ax to A

Increased Plasma Apolipoprotein(a) Levels in IDDM Patients With Diabetic Nephropathy

(9). In the IL1RI gene, a PCR and subsequent Pst I digestion resulted in a fragment of 362 bp (3.2 allele) or fragments of 256 and 108 bp

Effect of short-term hyperglycaemia on haemodynamics in type 1 diabetic patients

OBJECTIVE The relative mortality from cardiovascular disease (CVD) is increased 40-fold in IDDM patients suffering from diabetic nephropathy as compared with nondiabetic subjects on average. We assessed the potential contribution of dyslipidemia in general and elevated serum apolipoprotein (a) [apo(a)] in particular to CVD in nephropathic patients with IDDM. RESEARCH DESIGN AND METHODS We investigated 199 IDDM patients with diabetic nephropathy and 192 normoalbuminuric IDDM patients matched for sex, age, diabetes duration, and BMI. RESULTS The prevalence of CVD was 30 and 12% in patients with and without nephropathy, respectively (P < 0.001). The level of apo(a) was significantly higher in patients with nephropathy, 189 (20–2,350) U/l as compared with the normoalbuminuric group, 103 (20–1,940) U/l (P < 0.005). The prevalence of plasma apo(a) > 300 U/l (at-risk level for cardiovascular pathogenicity) was 38% (31–45) vs. 22% (16–28) in patients with and without nephropathy, respectively (P < 0.0005). In nephropathic patients, the prevalence of plasma apo(a) > 300 U/l was raised in patients with CVD (48%, 36–61%) as compared with patients without (34%, 26–42%) (P = 0.05). Furthermore, the serum concentrations of the following apolipoproteins and lipids were higher in patients with nephropathy as compared with normoalbuminuric patients: apoB 1.33 ± 0.37 vs. 1.06 ± 0.26 g/l; total cholesterol 5.6 ± 1.2 vs. 4.8 ± 0.9 mmol/l; and triglycerides 1.22 (0.31–9.87) vs. 0.77 (0.28–3.05) mmol/l, P < 0.0001. Multiple logistic regression analysis of cardiovascular risk factors revealed that plasma apo(a) concentration > 300 U/l is an independent risk factor for coronary heart disease, odds ratio 1.86 (1.03–3.36) (P < 0.05). CONCLUSIONS Dyslipidemia and raised plasma concentrations of apo(a), particularly > 300 U/l, may contribute to the enhanced morbidity and mortality from CVD characteristically observed in IDDM patients with diabetic nephropathy.

Renoprotective effects of angiotensin II receptor blockade in type 1 diabetic patients with diabetic nephropathy

Abstract. Jacobsen P, Rossing K, Hansen BV, Bie P, Vaag A, Parving H‐H (Steno Diabetes Center, Gentofte; University of Aarhus, Aarhus; and University of Southern Denmark, Odense, Denmark). Effect of short‐term hyperglycaemia on haemodynamics in type 1 diabetic patients. J Intern Med 2003; 254: 464–471.