Carotid intima media thickness (CIMT) in adults in the AWI-Gen Nairobi site study: Profiles and predictors

BACKGROUND

Carotid intima media thickness (CIMT) is used as a marker of subclinical and asymptomatic atherosclerotic vascular disease. Increased CIMT is associated with future cerebrovascular and cardiovascular events. There is limited data on the profile and correlates of CIMT in Africa. The aim of this study was to describe the profile and correlates of CIMT in apparently normal younger-age adults in an urban setting in Kenya.

METHODS

This study used population-based data collected from 2003 adults between the ages of 40 and 60 years in two slums of Nairobi as part of a genetic study. CIMT was measured using LOGIQ e (GE Healthcare, CT, USA) ultrasound on both left and right carotid arteries, whereby maximum, mean, and minimum values were recorded. Age- and sex-specific CIMT measurements were calculated and their association with basic sociodemographic, behavioral and body composition indicators were investigated.

RESULTS

The median (IQR) CIMT were 0.58 (0.51, 0.66) and 0.59 (0.53, 0.66) in men and women, respectively. About 16% of the study population had CIMT greater than 0.7mm, the cut off for higher CIMT. Nearly 60% had CIMT values ≥75th percentile. Age, current use of alcohol, systolic blood pressure, subcutaneous fat thickness, pulse rate and pulse pressure were found to be the main predictors of CIMT in our study population.

CONCLUSION

This study provided population-based reference values and predictors for CIMT for an adult population living in urban poor settings in Kenya. Future studies need to consider biochemical and genetic predictors of CIMT in this population.

Could a nonfunctional adrenal incidentaloma be a risk factor for increased carotid intima-media thickness and metabolic syndrome

BACKGROUND

This study was designed to detect the potential association of a nonfunctional adrenal incidentaloma (NFAI) with insulin resistance and associated metabolic disturbances, with a subsequent increase in cardiovascular risk factors.

METHODS

Eighty-three NFAI patients and 56 volunteers (controls) without any adrenal abnormalities on computed tomography (CT) were included. Fasting blood glucose (FBG), fasting insulin, lipid profiles, uric acid, homocysteine, fibrinogen, high sensitivity C-reactive protein (hs-CRP), and adiponectin levels were measured in both groups. Blood pressure (BP), waist circumference, body mass index (BMI), and carotid intima media thickness (CIMT) were evaluated in both the patients and volunteers.

RESULTS

There were no significant difference between the NFAI and control groups with respect to age, sex, BMI, waist circumference, systolic and diastolic BP, smoking, concomitant disease, and medications. Fasting insulin and glucose levels and homeostasis model of assessment-insulin resistance (HOMA-IR) scores were significantly higher in the NFAI group as compared with those in the control group (p<0.01). The frequency of metabolic syndrome in the NFAI group was higher than that in the control group (p<0.01). All the lipid fractions, except triglyceride (TG), (p<0.05), homocysteine (p=0.01), and fibrinogen levels (p<0.001), were significantly higher in the NFAI group as compared with the levels in the control group. There were no significant differences between the NFAI and control groups in terms of uric acid, hs-CRP, and adiponectin levels. The CIMT values in the NFAI group were significantly higher than those in the control group (0.74±0.14 vs. 0.53±0.09, p<0.001). The mean CIMT value showed a statistically positive correlation with age (r=0.245, p=0.004); the HOMA-IR score (r=0.490, p<0.001); and FBG (r=0.521, p<0.001), fasting insulin (r=0.432, p<0.001), total cholesterol (TC) (r=0.267, p=0.002), and fibrinogen (r=0.398, p<0.001) levels in the NFAI group.

CONCLUSIONS

The results indicated that the NFAI patients had an elevated risk of insulin resistance, with metabolic syndrome and increased CIMT values. Long-term follow-up studies should be designed to evaluate postsurgical alterations in metabolic parameters and cardiovascular risk factors in NFAI patients.