Blood pressure and glomerular filtration rate in youth with tuberous sclerosis complex

Renal involvement is very common in tuberous sclerosis complex (TSC) and is characterized by the development of angiomyolipoma and cysts. The aims of the present study were to assess kidney function and clinical features of renal involvement in TSC, including kidney function and blood pressure (BP) levels in children, adolescents and young adults. Non-selected patients with a definite diagnosis of TSC attending the paediatric neurology outpatient department of a tertiary hospital were included in a cross-sectional study. All participants had a renal imaging study within 6 months of ambulatory blood pressure (BP) and glomerular filtration rate (GFR) assessment. Data on demographics, history, genotype, kidney function at diagnosis and last imaging were collected. Twenty patients were enrolled in this study with a median age of 15 years (IQR range 9 to 18). About 23.5% of the participants had ambulatory hypertension. Systolic BP levels correlated significantly with GFR_DTPA values despite the absence of hyperfiltration. Patients that developed hypertension and possibly those with angiomyolipoma or cysts had higher GFR levels in childhood and adolescence. All the patients with ambulatory hypertension had angiomyolipoma or cysts on renal imaging studies.

Hypertension may present with increased frequency in young patients with kidney disease associated with TSC. Routine ambulatory BP measurement should be part of the annual clinical assessment in patients with TSC.

• Nearly half of the patients with TSC have a premature decline in their renal function in their fifth decade of life. • Hypertension and hyperfiltration have been proposed as modifiable factors of progression of renal decline in patients with TSC-related renal disease.

• Hypertension is prevalent in youth with tuberous sclerosis complex. • SBP levels have a positive relation with GFR levels within the normal range of GFRDTPA values.