The long-term cost of patients with diabetes who undergo CABG will add $84 million to the health system in China, according to a study that found China has the highest prevalence rate for diabetes mellitus in the world. The U.S. is not far behind, though.

Heng Zhang, MD, of Fuwai Hospital in Beijing, and colleagues published a study in the June issue of Annals of Thoracic Surgery that assessed the clinical and economic outcomes of patients with diabetes who underwent CABG between 1999 and 2008 at the hospital. The primary outcome was death and major adverse cardiovascular and cerebrovascular events (MACCE) with a follow-up of two years.

Of the 9,240 patients, 2,682 were diabetic. Zhang et al further stratified the diabetic patients into three groups: those who were insulin dependent (481 patients); those treated with medications (1,826) and those whose disease was controlled by diet (375). They had follow-up data on 96.3 percent of patients.

They found that the proportion of CABG patients with diabetes increased from 33.4 percent in 1999 to 40.4 percent in 2008. In-hospital mortality was 1.2 percent for patients with diabetes and 1 percent for those without diabetes. In adjusted analyses, diabetes was associated with an increased risk of long-term MACCE. Patients with insulin-controlled or medication-controlled diabetes were at higher risk of MACCE at five years compared with nondiabetic patients but the diet-controlled group had no increased risk.

Patients with diabetes had higher in-hospital costs, at $8,368 vs. $8,255. They also had higher long-term costs, costing an additional $1,623 per patient at two years. The researchers attributed much of the higher long-term costs to medication use.

They noted that the prevalence rate for diabetes was 11.3 percent in the U.S. Their research showed a rate of 11.6 percent in China, which they wrote was the highest rate in the world. An additional 1 million people are projected to develop diabetes in China annually as well.

Based on purchasing power parity equations, the in-hospital costs for CABG in China totaled $35,000.  By comparison, the cost in the U.S. was $34,467. They calculated that diabetes added an incremental cost burden of $84 million.

“The rising incidence of DM [diabetes mellitus], combined with the significant incremental costs, provides new clinical, economic and social challenges for the Chinese healthcare system,” they wrote.