BACKGROUND: Capillary leakage of sodium-fluorescein (NaF) in the skin reflects capillary permeability and may be a marker of diabetes-associated microcirculatory abnormalities. DESIGN: We evaluated transcapillary skin NaF leakage by fluorescence videodensitometry in 10 normoalbuminuric, 10 microalbuminuric Type 1 diabetic men (diabetes duration > 10 years) and 10 healthy subjects. The microalbuminuric patients were restudied after 6 weeks treatment with the ACE-inhibitor enalapril, 10 mg once daily. All measurements were performed at a blood glucose level of 5 mmol L-1. RESULTS: Transcapillary NaF leakage was strongly increased in normoalbuminuric Type 1 diabetic patients compared to healthy subjects (P < 0.001) and was still further increased in microalbuminuric Type 1 diabetic patients (P < 0.01 compared to normoalbuminuric patients). Enalapril reduced NaF leakage (P < 0.05), mean arterial blood pressure (P < 0.05) and microalbuminuria (P < 0. 05). After treatment, NaF leakage was not different from that in normoalbuminuric patients. CONCLUSIONS: Capillary permeability, as determined by NaF leakage, is elevated in normoalbuminuric Type 1 diabetic patients with long-standing disease, and the excess elevation in microalbuminuric Type 1 diabetic patients is ameliorated by ACE-inhibition. Skin NaF videodensitometry seems a useful tool to document capillary permeability in intervention studies.
BACKGROUND: Capillary leakage of sodium-fluorescein (NaF) in the skin reflects capillary permeability and may be a marker of diabetes-associated microcirculatory abnormalities. DESIGN: We evaluated transcapillary skin NaF leakage by fluorescence videodensitometry in 10 normoalbuminuric, 10 microalbuminuric Type 1 diabeticmen (diabetes duration > 10 years) and 10 healthy subjects. The microalbuminuric patients were restudied after 6 weeks treatment with the ACE-inhibitor enalapril, 10 mg once daily. All measurements were performed at a blood glucose level of 5 mmol L-1. RESULTS: Transcapillary NaF leakage was strongly increased in normoalbuminuric Type 1 diabeticpatients compared to healthy subjects (P < 0.001) and was still further increased in microalbuminuric Type 1 diabeticpatients (P < 0.01 compared to normoalbuminuric patients). Enalapril reduced NaF leakage (P < 0.05), mean arterial blood pressure (P < 0.05) and microalbuminuria (P < 0. 05). After treatment, NaF leakage was not different from that in normoalbuminuric patients. CONCLUSIONS: Capillary permeability, as determined by NaF leakage, is elevated in normoalbuminuric Type 1 diabeticpatients with long-standing disease, and the excess elevation in microalbuminuric Type 1 diabeticpatients is ameliorated by ACE-inhibition. Skin NaF videodensitometry seems a useful tool to document capillary permeability in intervention studies.