The SA Journal Diabetes & Vascular Disease Vol 15 No 1 (July 2018)

SA JOURNAL OF DIABETES & VASCULAR DISEASE

RESEARCH ARTICLE

VOLUME 15 NUMBER 1 • JULY 2018

needed for institution of appropriate primary prevention measures

in patients at risk for diabetes.

The Framingham risk-assessment tool, which was developed

in the general population and validated in people with diabetes,

is used to estimate a person’s 10-year risk of developing CVD in

order to identify high-risk individuals for primary prevention.

An individual’s risk score can aid clinical decision making on how

intensively to intervene in lifestyle-modification strategies, when

to include drug therapy,

and also to assess the efficacy of these

interventions.

This study compared the cardiovascular risk scores of type 2

diabetes subjects on treatment, with those of individuals with the

metabolic syndrome, and healthy controls. It examined the impact

of glycaemic control and lifestyle on cardiovascular risk reduction in

adult Nigerians.

Methods

This was a cross-sectional study of 40 adult men and women with

type 2 diabetes mellitus (DM), 40 adult men and women with

the metabolic syndrome, and 40 age- and gender-matched males

and females who were recruited as healthy controls. The Ethical

Research and Review Committee of the Lagos University Teaching

Hospital (LUTH) approved the study protocol, and informed consent

was obtained from the participants.

The study participants were patients attending the Diabetic

Clinic and the Obesity and Metabolic Clinic of the Lagos University

Teaching Hospital. Adult men and women between the age

of 30 and 70 years who agreed to participate in the study were

consecutively recruited. Socio-demographic and clinical data were

obtained from the participants using a structured questionnaire.

Anthropometric measurements such as weight, height, waist and

hip circumference and blood pressure readings were taken. Lipid

profile results were also determined.

The diagnosis of type 2 diabetes was based on the WHO

criteria,

and the diagnosis of the metabolic syndrome was based

on the NCEP-ATPIII criteria.

Subjects who did not meet the criteria

for the metabolic syndrome were matched for age and gender with

the cases and recruited as controls.

The inclusion criteria included adult males and females between

30 and 70 years of age who had been diagnosed as having DM

by the WHO criteria,

with a blood glucose level controlled with

diet and hypoglycaemic drugs, and non-diabetics who had the

metabolic syndrome, described by the presence of any three of

the following: abdominal circumference ≥ 102 cm in males or

≥ 88 cm in females, high-density lipoprotein cholesterol (HDL-C)

< 1.03 mmol/l (< 40 mg/dl) in males or < 1.3 mmol/l (< 50 mg/

dl) in females, triglycerides (TG) ≥ 1.7 mmol/l (≥ 150 mg/dl), blood

pressure ≥ 130/85 mmHg or the patient receiving hypotensive

treatment, and fasting glycaemia > 6.1 mmol/l (> 110 mg/dl).

Pregnant women were excluded from the study.

The study participants reported on the morning of the study

after an overnight (10–12 hours) fast; 5 ml of venous blood was

collected from the ante cubital vein and transferred into plain tubes

for lipid profile assay, into fluoride oxalate tubes for glucose analysis,

and into EDTA tubes for glycated haemoglobin (HbA

) assay.

Abdominal obesity was determined by measurement of the

waist circumference. The measurement was taken using an inelastic

tape, at the end of several consecutive natural breaths, at a level

parallel to the floor, midpoint between the top of the iliac crest and

the lower margin of the last palpable rib in the mid-axillary line.

The hip circumference was measured at a level parallel to the floor,

at the largest circumference of the buttocks.

Blood pressure was determined using the Accoson’s mercury

sphygmomanometer (cuff size 15 × 43 cm). The subjects were

seated and rested for five minutes before measurement. Systolic

blood pressure was taken at the first Korotkoff sound and diastolic

at the fifth Korotkoff sound.

Total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C),

HDL-C and triglyceride levels were determined on fasting serum

samples, and glucose concentrations were determined from fasting

fluoride oxalate plasma using reagents from Randox Laboratories

Ltd (Antrim, UK, BT 29 4QY) on a semi-automatic biochemistry

analyser (BS3000P-Sinnowa Medical Science and Technology Co,

Ltd, Nanjing, China, 211135). An ion-exchange chromatographic-

spectrophotometric method was used for HbA

determination,

with reagents from Fortress Diagnostics, UK. The Framingham risk

score was estimated from a cardiovascular disease risk calculator

based on the equation from the Framingham heart study.

Table 1.

Gender and age distribution of the study participants

Characteristics

Subjects

with type 2

diabetes

= 40 (%)

Subjects with

the metabolic

syndrome

= 40 (%)

Healthy

controls

= 40 (%)

-value

Gender

Males

13 (32.55)

1.00

Females

27 (67.5)

Age (mean ± SD)

55.65 ± 10.54 54.87 ± 9.80 56.17 ± 10.2 0.78

Age group (years)

30–40

5 (12.5)

7 (17.5)

0.83

41–50

14 (35)

15 (37.5)

12 (30)

51–60

18 (45)

19 (47.5)

61–70

3 (7.5)

2 (5)

Table 2.

Socio-demographic characteristics of the study participants

Characteristics

Subjects with

type 2 diabetes

= 40 (%)

Subjects with

the metabolic

syndrome

= 40 (%)

Healthy

controls

= 40

(%)

-value

Level of Education

None

2 (5)

0 (0)

1 (2.5)

0.075

Primary

9 (22.5)

3 (7.5)

5 (12.5)

Secondary

13 (32.5)

11 (27.5)

6 (15)

Tertiary

6 (15)

26 (65)

28 (70)

Exercise

Yes

5 (12.5)

6 (15)

4 (10)

0.81

35 (87.5)

34 (85)

36 (90)

Alcohol

Yes

11 (27.5)

6 (15)

0.64

29 (72.5)

34 (85)

Smoking

Yes

0 (0)

2 (5)

3 (7.5)

0.86

40 (100)

38 (95)

37 (92.5)