Arterial hypertension and type 2 diabetes are frequent in iNPH

Introduction

Association of hypertension and diabetes with idiopathic normal pressure hydrocephalus (iNPH) has been described earlier, however, the prognostic role of these comorbidities is unknown.

Methods

All available hospital records and causes of death were reviewed retrospectively from a cohort of 283 iNPH patients with a median follow-up of 5.6 years (range 0.04–19.9 years) from a defined population in Middle and Eastern Finland.

Results

A total of 148 patients (52.3%) were hypertensive and 65 patients (23.0%) diabetic. Both diseases were equally distributed among sexes, and no age differences were observed between groups. In addition, short-term shunt-response was similar with a total of 85.1% of the 269 shunted patients showing a positive response. Mortality between diabetic and non-diabetic patients was similar (58.5% vs. 48.6%, p = 0.16), however, median survival time was significantly lower in patients with diabetes compared to non-diabetic iNPH patients (6.3 vs. 9.8 years, log rank test p < 0.001). No statistically significant differences of mortality or survival time were observed in hypertensive vs. non-hypertensive patients. The most frequent cause of death among all groups was coronary heart disease.

Conclusions

Both hypertension and diabetes are common in iNPH. A comorbid type 2 diabetes is a significant risk factor for earlier death.