The SA Journal Diabetes & Vascular Disease Volume 18 No 2 (November 2021)

RESEARCH ARTICLE SA JOURNAL OF DIABETES & VASCULAR DISEASE 20 VOLUME 18 NUMBER 2 • November 2021 min/1.73m 2 . 28 Dyslipidaemia was defined as total cholesterol (TC) > 240 mg/dl (6.22 mmol/l) or low-density lipoprotein cholesterol (LDL-C) > 100 mg/dl (2.59 mmol/l) or high-density lipoprotein cholesterol (HDL-C) < 40 mg/dl (1.04 mmol/l) or triglycerides (TG) > 150 mg/dl (1.7 mmol/l). 29 Elevated RI was defined as a value > 0.70. 30 Statistical analysis Statistical analysis was carried out using the statistical package for social sciences (SPSS) version 20 (SPSS Inc, Chicago, IL). Continuous data are presented as mean ± standard deviation and categorical variables are expressed as proportions or percentages. ANOVA was used for comparison of the three groups’ means with post hoc t -tests to determine the points of difference, while the chi-squared test ( χ 2 tests) was applied for comparison of categorical variables in subjects and controls. Spearman’s rank correlation was used to determine correlations between RI and eGFR and UACR, while one-way ANOVA was used to compare RI and other continuous variables across the three groups. Regression analysis was carried out to determine variables independently associated with elevated RI and statistical significance was set at p = 0.05. Results A total of 133 subjects participated in the study, 40 individuals with DM without DN, 53 participants with DM with DN, and 40 healthy controls. The mean ages across the three arms were 57.0 ± 6.8, 54.7 ± 9.4 and 52.9 ± 6.4 years ( p = 0.08) for subjects with DM without DN, those with DM with DN and the healthy controls, respectively (Table 1). There were more males among the group with DM without DN compared to the other two arms, while most of the participants in all three groups were married and had at least primary school education (Table 1). The diastolic blood pressure (DBP) (79.6 ± 11.2, 78.9 ± 11.1 and 73.3 ± 8.3 mmHg, p = 0.01) and systolic blood pressure (SBP) (126.2 ± 17.1, 126.5 ± 18.2 and 109.9 ± 11.3 mmHg, p = 0.07) were higher among the groups of DM with DN and DM without DN compared to the healthy controls, respectively (Table 2). The mean FPG level in those with DM without DN (98 ± 12.8 mg/dl = 5.4 ± 0.71 mmol/l) and those with DM with DN (102 ± 15.1 mg/dl = 5.55 ± 0.84 mmol/l) were higher than in the healthy controls (84 ± 10.5 mg/dl ± 4.66 ± 0.58 mmol/l) ( p = 0.02), while mean HbA 1c level in the subjects with DM without DN (7.0 ± 1.7%) and those with DM with DN (7.0 ± 1.4%) were higher than in the healthy controls (5.1 ± 0.9%) ( p = 0.02) (Table 2). The mean UACR was higher among the subjects with DM with DN (98.3 ± 45 mg/g) compared to participants with DM without DN (30.5 ± 18 mg/g) and healthy controls (23.1 ± 15 mg/g) ( p = 0.01). Similarly the mean eGFR was significantly lower among participants with DM with DN and DM without DN compared to the healthy controls (52 ± 15.4, 86 ± 32.2, 101 ± 27.9 ml/min/1.73m 2 , respectively) ( p = 0.2) (Table 2). The mean right interlobar artery RI among participants with DM without DN, those with DM with DN and the healthy controls was 0.58 ± 0.05, 0.61 ± 0.05 and 0.54 ± 0.04, respectively ( p = 0.04), while the left interlobar artery RIs were similar in all three groups (Table 3). The prevalence of low RI among participants with DM without DN, DM with DN and controls were 12 (30.0%), 23 (43.4%) and 5 (12.5%), respectively (Table 3). The post hoc analysis showed no significant difference in the mean RI and the prevalence Table 1. Baseline characteristics of the participants DM DM Healthy without DN with DN controls [mean ± SD/ [mean ± SD/ [mean ± SD/ frequency frequency frequency (%)] (%)] (%)] Characteristics ( n = 40) ( n = 53) ( n = 40) p -value Mean age (years) 57.0 ± 6.8 54.7 ± 9.4 52.9 ± 6.4 0.08 Age ≥ 65 years 15 (37.5) 22 (41.5) 18 (45.0) Gender Male 21 (51.2) 11 (20.7) 11 (27.5) 0.03 Female 19 (48.8) 42 (79.3) 29 (72.5) Marital status Married 35 (85.4) 44 (84.6) 38 (95.0) 0.15 Single 5 (12.5) 6 (11.3) 2 (5.0) Divorced/widowed 0 (0) 3 (5.7) 0 (0) Educational status Primary 19 (46.3) 21 (39.62) 20 (52.6) 0.30 Secondary 14 (34.2) 13 (24.5) 15 (39.5) Tertiary 7 (17.5) 19 (35.8) 5 (12.5) DM: diabetes mellitus; DN: diabetic nephropathy. Table 2. Clinical and laboratory characteristics of the participants DM DM Healthy without DN with DN controls [mean ± SD/ [mean ± SD/ [mean ± SD/ frequency frequency frequency (%)] (%)] (%)] Variables ( n = 40) ( n = 53) ( n = 40) p -value BMI (kg/m 2 ) 27.0 ± 4.9 26.5 ± 5.0 25.2 ± 2.9 WHR (cm) 1.0 ± 0.2 1.0 ± 0.1 0.9 ± 0.1 0.91 DBP (mmHg) 79.6 ± 11.2 78.9 ± 11.1 73.3 ± 8.3 0.02 SBP (mmHg) 126.2 ± 17.1 126.5 ± 18.2 109.9 ± 11.3 0.07 FPG (mg/dl) 98 ± 12.8 102 ± 15.1 84 ± 10.5 0.02 HbA 1c (%) 7.0 ± 1.7 7.0 ± 1.4 5.1 ± 0.9 0.02 TC (mg/dl) 165.4 ± 31.1 173.2 ± 59.4 140.6 ± 41.1 0.01 (mmol/l) 4.28 ± 0.81 4.49 ± 1.54 3.64 ± 1.06 LDL-C (mg/dl) 105.7 ± 45.1 104.4 ± 47.7 76.9 ± 22.3 0.01 (mmol/l) 2.74 ± 1.17 2.70 ± 1.24 1.99 ± 0.58 HDL-C (mg/dl) 43.4 ± 14.8 41.1 ± 14.4 43.4 ± 14.1 0.10 (mmol/l) 1.12 ± 0.38 1.06 ± 0.37 1.12 ± 0.37 TG (mg/dl) 103.3 ± 29.4 121.6 ± 41.2 104.5 ± 31.6 0.06 (mmol/l) 1.17 ± 0.33 1.27 ± 0.47 1.18 ± 0.36 eGFR 86 ± 32.2 52 ± 15.4 101 ± 27.9 0.02 (ml/min/1.73 m 2 ) UACR (mg/g) 30.5 ± 18.4 98.3 ± 45 23.1 ± 12.2 0.01 PCV 35.8 32 ± 3.8 36.7 ± 5.4 0.21 Hypertension 19 (46.3) 33 (62.2) 0 (0) 0.01 On antihypertensives 15 (37.5) 23 (43.4) 0 (0) 0.97 On ACE 11 (27.5) 18 (34.0) 0 (0) 0.51 Duration of DM 16 (40) 25 (47.2) 0 (0) 0.49 (> 5 years) Elevated HbA 1c 16 (40) 14 (26.4) 0 (0) Dyslipidaemia 23 (57.5) 28 (52.8) 11 (27.5) DM: diabetes mellitus; DN: diabetes nephropathy; BMI: body mass index; WHR: waist–hip ratio; DBP: diastolic blood pressure; SBP: systolic blood pressure; FPG: fasting plasma glucose; HbA 1c : haemoglobin A 1c ; TC: total cholesterol; LDL-C: low-density lipoprotein cholesterol; HDL-C: high-density lipoprotein cholesterol; TG: triglycerides; eGFR: estimated glomerular filtration rate; UACR: urinary albumin–creatinine ratio; PCV: packed cell volume; ACEI: angiotensin converting enzyme inhibitor.