Coexisting hypertension is the leading risk factor for mortality among younger type 2 diabetes patients, while among the older patients, chronic kidney disease (CKD)  is the major mortality risk, according to a study published in PLoS Medicine.¹

A total of 360,202 Chinese adults with type 2 diabetes were included in this prospective study. Data was obtained from the Risk Assessment and Management Programme for Diabetes Mellitus (RAMP-DM), a diabetes complication screening program in Hong Kong between January 2000 and December 2019; 52.4% of them were men. The study objective was to explore the age-wise association with various risk factors for all-cause and cause-specific mortality. Eight risk factors were investigated: cardiovascular disease (CVD), chronic kidney disease (CKD), all-site cancer, suboptimal BP, suboptimal HbA1c, suboptimal low-density lipoprotein cholesterol (LDL-C),  suboptimal body weight and smoking. The participants were divided into four age groups for the analysis: 18 to 54, 55 to 64, 65 to 74, and ≥75 years.

Overall, ~17% of the study subjects had CVD, 14% had CKD and 4.3% had all-site cancer. Nearly 14% were current smokers; 60% had suboptimal body weight. Half of the participants had less than optimal glycemic control, 33.5% had suboptimal control of BP and 54% had inadequately controlled LDL-C.

A total of 44,396 deaths occurred during the median follow-up duration of 6.0 years. The leading causes of death were pneumonia, CVD and cancer. All the eight risk factors, except suboptimal LDL-C, were associated with all-cause mortality risk. The absolute mortality risk was 10 times higher among the older participants aged ≥75 years compared to those in the age group 18-54 years; 59.7 versus 596.2 per 10,000 person-years. The association of the risk factors with increased mortality was however more pronounced among the youngest participants with PAF of 51.6% vs 35.3%, among the oldest participants in the age group of 75 years and above.

The main attributable risk factor for all-cause mortality among the participants aged 18–54 years was suboptimal BP with PAF of 16.9% followed by CKD with PAF of 13.2% and smoking with PAF of 11.4%. Among the oldest participants, the major attributable risk factors were CKD (PAF 15.2%), CVD (PAF 9.2%) and suboptimal bodyweight (PAF 7.1%).

This study establishes that the major risk factors for mortality among patients with type 2 diabetes vary in different age groups. Among the younger diabetics, suboptimal control of BP was the most common risk factor, whereas among the older patients, CKD was the leading risk factor.

The 2023 American Diabetes Association (ADA) Standards of Care in Diabetes recognize hypertension as a “strong risk factor for the development and progression of CKD”. It is also a risk factor for ASCVD. ADA now defines HT as systolic BP ≥130 mmHg or a diastolic BP ≥80 mmHg. Hence, a target BP less than 130/80 mmHg is recommended for all patients with diabetes. Early control of BP will prevent/delay development of future CKD and also help reduce cardiovascular mortality.

Reference

1. Wu H, et al. Age-specific population attributable risk factors for all-cause and cause-specific mortality in type 2 diabetes: An analysis of a 6-year prospective cohort study of over 360,000 people in Hong Kong. PLoS Med. 2023 Jan 30;20(1):e1004173. doi: 10.1371/journal.pmed.1004173.