Diabetes duration and hypertension drive cardiovascular risk in Nigerian patients with type 2 diabetes

Among 150 randomly selected patients receiving specialist diabetes care, 42.7 percent fell into moderate or high risk categories on a World Health Organization risk chart validated for Western sub-Saharan Africa, while 57.3 percent were classified as low risk. The work, published in Discover Endocrinology and Metabolism, offers a detailed snapshot of cardiovascular risk stratification in a population where such data have been sparse.

The research team, led by Jamila Aminu Mohammed and colleagues, assessed ten-year risk of a fatal or non-fatal cardiovascular event using the updated WHO laboratory-based risk assessment chart, which incorporates age, sex, systolic blood pressure, smoking status, diabetes status and total cholesterol. Participants were initially sorted into four bands: very low risk below five percent, low risk from five to under ten percent, moderate risk from ten to under twenty percent, and high risk at twenty percent or above. In the final cohort, 19.3 percent of patients sat in the very low band, 38.0 percent in the low band, 38.7 percent in the moderate band and 4.0 percent in the high band. For analysis, the researchers merged the two lowest bands into a low-risk group and the two highest into an elevated-risk group, reflecting their similar implications for preventive decision-making.

Only 6 of the 150 participants, or 4.0 percent, landed in the highest risk category, and the authors suggest this may reflect the benefits of access to specialized care and the relatively young age structure of the cohort, which ranged from 38 to 65 years with a mean of 52.5. Nevertheless, the overall share of patients at elevated risk remained substantial despite their attendance at a dedicated diabetic clinic within a 400-bed referral hospital serving Abuja and neighbouring North-Central states. The clinic handles an average of 50 patients per clinic day and roughly 200 patients monthly, making the findings a window into the current state of specialist diabetes management in Nigeria’s federal capital.

To identify what distinguished patients at elevated risk from those at low risk, the team compared demographic, clinical and biochemical characteristics across the two groups. Patients in the elevated-risk category were markedly older, with a median age of 60.5 years compared with 47.0 years among low-risk patients, and had lived with diabetes far longer, a median of 10.0 years versus 3.0 years. Systolic blood pressure was significantly higher in the elevated-risk group, and co-morbid hypertension, defined as systolic pressure of at least 140 mmHg, diastolic pressure of at least 90 mmHg or current use of antihypertensive medication, was present in 53.1 percent of elevated-risk patients compared with 19.8 percent of those at low risk.

Sex and employment status also differed between the groups. A higher proportion of women appeared in the low-risk category, 62.8 percent versus 46.9 percent, while employment was more common among low-risk patients and retirement more common among those at elevated risk. However, several other measures showed no significant differences, including body mass index, glycaemic control assessed by HbA1c, the full lipid profile, high-sensitivity C-reactive protein, smoking status, alcohol consumption, ethnicity and the approach to diabetes management. Current or recent smoking was uncommon overall, reported by only 9 participants, or 6.0 percent of the cohort.

The researchers then fitted a binary logistic regression model to determine which factors independently predicted elevated cardiovascular risk. The model included duration of diabetes, co-morbid hypertension, use of antihypertensive therapy and use of lipid-lowering therapy, while employment status was excluded to avoid collinearity with age. Variables that feed directly into the WHO risk chart, such as age, systolic blood pressure, total cholesterol and smoking status, were left out of the model to prevent multicollinearity. The final model performed well, explaining 49.6 percent of the variance in risk status according to the Nagelkerke R-squared, correctly classifying 74.0 percent of cases and passing the Hosmer-Lemeshow goodness-of-fit test.

Two determinants emerged as statistically significant. Each additional year of diabetes duration raised the odds of elevated cardiovascular risk by 26 percent, with an adjusted odds ratio of 1.26 and a 95 percent confidence interval of 1.15 to 1.39. The presence of co-morbid hypertension nearly quintupled the odds, with an adjusted odds ratio of 4.69 and a 95 percent confidence interval of 1.81 to 12.19. Antihypertensive therapy and lipid-lowering therapy both showed trends toward reduced odds of elevated risk, with adjusted odds ratios of 0.52 and 0.68 respectively, but neither association reached statistical significance, with p values of 0.187 and 0.682.

The authors interpret the strong effect of diabetes duration through the lens of prolonged metabolic exposure. Chronic hyperglycaemia drives endothelial dysfunction, oxidative stress and low-grade inflammation, processes that accelerate atherosclerosis and can inflict vascular damage that persists even after blood glucose is later brought under control, a phenomenon often described as glycaemic memory. They also note that in low-resource settings, type 2 diabetes frequently goes undiagnosed for years, meaning the true duration of disease exposure, and therefore the accumulated cardiovascular risk, may be even greater than the recorded figures suggest. The synergistic interplay between elevated blood pressure and hyperglycaemia, they argue, underscores the importance of rigorous blood pressure control as a cornerstone of cardiovascular prevention in diabetes.

The study has clear limitations that shape how its findings should be read. Its cross-sectional design cannot establish causal relationships, and recruitment from a single specialized tertiary centre limits generalizability to the broader, potentially underserved population of Nigerians with type 2 diabetes, particularly those in rural areas with less access to preventive care. Reliance on self-reported data for medication adherence and lifestyle factors introduces the possibility of recall and social desirability bias, and unmeasured confounders such as dietary patterns and socioeconomic status may have influenced risk stratification. The WHO risk chart used is calibrated for individuals aged 40 and above, while the cohort included patients as young as 38, a deviation the authors judge to carry minimal potential for risk underestimation given the narrow age range.

Comparisons with earlier Nigerian studies suggest the observed burden may be higher than previously appreciated, partly because this study employed a risk scoring tool specifically validated for Western sub-Saharan Africa rather than surrogate markers or tools tailored to other populations. A recent Nigerian study using the same WHO chart reported a slightly higher prevalence of moderate-to-high cardiovascular risk, 51.5 percent, among its participants, a figure the authors attribute to differences in study populations, health system factors and levels of primary prevention. Taken together, the findings point to a persistent cardiovascular burden among patients already receiving specialist diabetes care and reinforce the case for early, sustained and multi-targeted interventions, particularly in resource-limited settings where the unmet need may be even greater than this urban tertiary cohort reveals.

Subject of Research: Cardiovascular disease risk patterns and determinants among patients with type 2 diabetes receiving specialist care in Nigeria

Article Title: Patterns and determinants of cardiovascular disease risk in type 2 diabetes mellitus: insights from a tertiary care centre in Nigeria

Article References: Mohammed, J. A., Basil, B., Mba, I. N., Myke-Mbata, B. K., & Okoro, N. I. (2026). Patterns and determinants of cardiovascular disease risk in type 2 diabetes mellitus: insights from a tertiary care centre in Nigeria. Discover Endocrinology and Metabolism, 2(1), Article 11. https://doi.org/10.1007/s44417-026-00017-4

Image Credits: AI Generated

DOI: 10.1007/s44417-026-00017-4

Keywords: type 2 diabetes, cardiovascular disease risk, WHO risk chart, hypertension, diabetes duration, Nigeria, cross-sectional study, tertiary care, logistic regression, low- and middle-income countries, risk stratification, preventive cardiology