Acta Pzdiatr Scand 67: 219-224. 1978
RENAL FUNCTION IN ANOREXIA NERVOSA A. APERIA, 0. BROBERGER and L. FOHLIN From the Department of Paediatrics, Kuroiinska institute, St. Goran’s Hospital, Stockholm, Sweden
ABSTRACT. Aperia, A., Broberger, 0. and Foblin, L. (Department of Paediatrics, St. Goran’s Hospital, Stockholm, Sweden). Renal function in anorexia nervosa. Acta Paediatr Scand, 67:219, 1978.-Renal function was examined in twelve patients, eight girls and four boys, with anorexia nervosa (AN) ranging in age from 12.6 to 18.2 years. The weight loss at the time of the study averaged 26 %. Determinations were made of glomerular filtration rate (GFR), PAH clearence (CPAH)and urinary concentrating capacity. For references the same studies were also carried out in five healthy teenagers. Both GFR and C,, were generally reduced in AN. The reduction of GFR was, however, out of proportion to the reduction of C,,, as shown by a significantly lower filtration fraction (FF) in AN. Indirect evidence suggests that the low FF could be attributed to reduced water permeability of the glomerular capillary. The urinary concentrating capacity following fluid deprivation was moderately depressed both before and after the administration of vasopressin. The concentrating defect in AN must therefore be primary of renal origin. KEY WORDS: Kidney, anorexia nervosa, glomerular capillaries, urinary concentrating capacity, malnutrition
Anorexia nervosa (AN) is commonly reported to be associated by conflicting disturbances in fluid homeostasis such as edema (3, 9) and reduced urinary concentrating capacity ( 14). The origin of these disturbances is still unknown. This study was therefore undertaken to evaluate the role of the kidney in the control of fluid homeostasis in AN condition.
MATERIAL AND METHODS Eight female and four male patients suffering from anorexia nervosa were studied during the years 1975-1977. All patients conformed to the following criteria for diagnosis (chiefly from Dally (3)). 1. Age at onset less than 25 years 2. Active refusal to eat with accompanying pronounced weight loss 3. No evidence of schizophrenia, severe depression or organic disease. This study was supported by grants from the Swedish Medical Research Council (B77-19X-2049-10B) and by grants from the Karolinska Institute.
The physical characteristics of the patients are given in Table 1. All the patients, except two girls and one boy, are included in an enlarged study (7). The patients were treated at St. Goran’s Hospital for Children. None of the patients showed any signs of electrolyte disturbances. Blood volume per kg body weight averaged 79 ml, which corresponds well with normal data. The patients’ 24-hour excretion of aldosteron was on the lower normal level for the laboratory. Only one patient (UP) was on a medication (Thioridazin chloride, Mallorol@).Secondary amenorrhea was present in all postpubertal girls. The patients mean weight and height were 39.627.4 kg and 168.5+ 11.3 cm. Individual weight loss from premorbid weight is given in Table 1. For reference 5 healthy subjects were examined, four boys and one girl. Their age varied between 14.3 and 16.5 years (mean 14.8 years). Controls’ mean weight and height were 53.4k7.6 kg and 168.1f9.5 cm. The investigation was performed after the informed consent by all individual persons as well as by their parents and after the approval by the ethical Committee of Karolinska Institutet. All studies were performed within one week. The following tests were included in the study: Determination of maximal urine osmolality after fluid deprivation with and without pitressin; determination of the glomerular filtration rate (GFR) by the clearance of inulin; determination of renal blood flow by the clearance of PAH. Serum proActn Pzdiurr Scand 67
220
A . Aperia et al.
Table 1. Relevant clinical data in patients with AN n.s.=non significant ~
~
~
~~~~~~~
Patients
Sex
PC MS UP AN JJ ME CP AS YN PW GG
M M M M F F F F F F F F
KA M
S.D. Controls (n=5) M S.D.
Age (Y.)
Duration (Y.)
12.6 17.0 17.4 18.2 12.8 13.6 14.2 14.8 14.9 16.7 17.0 17.3 15.5 1.9
1 .o I .o I .o 1 .o 0.8 0.8 1.3 1 .o
0.6
1 .o
3.5 2.5 1.3 0.8
Weight loss (%)
Mean blood pressure (mmHg)
Serumprotein (g/b
27 23 27 23 35 24 15 26 15 31 38 31 26.3 7.0
84 74 80 88 68 84 81 82 76 76 72 82 78.9 5.8
63 68 63 79 72 63 68 74 68 63 64 69 67.8 5.1
97.0 4.0 10.001
70.2 3.4
14.8 0.9 n.s.
P
tein was analyzed with a refractometric method. Blood pressure was measured with a cuff and mean arterial blood pressure calculated as the diastolic pressure plus 40% of the pulse amplitude. Determination of maximal urine osmolality Nine of the patients were deprived of fluid and food for 17 hours starting at 5 o’clock p.m. Two to three urine sam-
n.s.
ples were obtained by spontaneous voiding and used for determination of osrnolality. The fluid deprivation test was repeated, but at this time an intramuscular injection of vasopressin (Pitressin tannate in oil@) in a dose of 0.5 pressor units/6 kg of body weight was given at the start of the fluid deprivation. Two to three urine samples obtained by spontaneous voiding were obtained after 17 hours and analyzed for urea and osmolality.
Table 2 . Renal hemodynamics in patients with A N n.s .=non significant
GFR Patients
I/hour
Ilhour 1.73 m2b.s.
I/hour
I/hour 1.73 m2 b.s.
FF
(%I
3.46 4.09 4.28 4.63 3.16 3.16 4.16 3.13 3.03 2.30 2.92 4.20
4.94 4.30 4.54 4.99 4.52 3.56 5.72 3.64 4.30 3.04 4.01 4.93
25.17 29.20 32.83 27.47 23.11 18.76 20.27 19.22 15.92 17.55 19.17 30.71
35.99 30.61 34.85 28.63 33.04 21.21 28.74 22.33 22.58 22.83 26.32 37.15
13.7 14.0 13.0 16.9 13.7 16.8 20.5 16.4 19.0 13.1 15.2 13.7
3.54 0.71
4.37 0.74
23.28 5.66
28.69 5.71
15.5 2.4
5.77 0.89
6.20 0.56
26.36 1.45
29.26 2.13
21.9 2.8
RENAL FUNCTION IN ANOREXIA NERVOSA A. APERIA, 0. BROBERGER and L. FOHLIN From the Department of Paediatrics, Kuroiinska institute, St. Goran’s Hospital, Stockholm, Sweden
ABSTRACT. Aperia, A., Broberger, 0. and Foblin, L. (Department of Paediatrics, St. Goran’s Hospital, Stockholm, Sweden). Renal function in anorexia nervosa. Acta Paediatr Scand, 67:219, 1978.-Renal function was examined in twelve patients, eight girls and four boys, with anorexia nervosa (AN) ranging in age from 12.6 to 18.2 years. The weight loss at the time of the study averaged 26 %. Determinations were made of glomerular filtration rate (GFR), PAH clearence (CPAH)and urinary concentrating capacity. For references the same studies were also carried out in five healthy teenagers. Both GFR and C,, were generally reduced in AN. The reduction of GFR was, however, out of proportion to the reduction of C,,, as shown by a significantly lower filtration fraction (FF) in AN. Indirect evidence suggests that the low FF could be attributed to reduced water permeability of the glomerular capillary. The urinary concentrating capacity following fluid deprivation was moderately depressed both before and after the administration of vasopressin. The concentrating defect in AN must therefore be primary of renal origin. KEY WORDS: Kidney, anorexia nervosa, glomerular capillaries, urinary concentrating capacity, malnutrition
Anorexia nervosa (AN) is commonly reported to be associated by conflicting disturbances in fluid homeostasis such as edema (3, 9) and reduced urinary concentrating capacity ( 14). The origin of these disturbances is still unknown. This study was therefore undertaken to evaluate the role of the kidney in the control of fluid homeostasis in AN condition.
MATERIAL AND METHODS Eight female and four male patients suffering from anorexia nervosa were studied during the years 1975-1977. All patients conformed to the following criteria for diagnosis (chiefly from Dally (3)). 1. Age at onset less than 25 years 2. Active refusal to eat with accompanying pronounced weight loss 3. No evidence of schizophrenia, severe depression or organic disease. This study was supported by grants from the Swedish Medical Research Council (B77-19X-2049-10B) and by grants from the Karolinska Institute.
The physical characteristics of the patients are given in Table 1. All the patients, except two girls and one boy, are included in an enlarged study (7). The patients were treated at St. Goran’s Hospital for Children. None of the patients showed any signs of electrolyte disturbances. Blood volume per kg body weight averaged 79 ml, which corresponds well with normal data. The patients’ 24-hour excretion of aldosteron was on the lower normal level for the laboratory. Only one patient (UP) was on a medication (Thioridazin chloride, Mallorol@).Secondary amenorrhea was present in all postpubertal girls. The patients mean weight and height were 39.627.4 kg and 168.5+ 11.3 cm. Individual weight loss from premorbid weight is given in Table 1. For reference 5 healthy subjects were examined, four boys and one girl. Their age varied between 14.3 and 16.5 years (mean 14.8 years). Controls’ mean weight and height were 53.4k7.6 kg and 168.1f9.5 cm. The investigation was performed after the informed consent by all individual persons as well as by their parents and after the approval by the ethical Committee of Karolinska Institutet. All studies were performed within one week. The following tests were included in the study: Determination of maximal urine osmolality after fluid deprivation with and without pitressin; determination of the glomerular filtration rate (GFR) by the clearance of inulin; determination of renal blood flow by the clearance of PAH. Serum proActn Pzdiurr Scand 67
220
A . Aperia et al.
Table 1. Relevant clinical data in patients with AN n.s.=non significant ~
~
~
~~~~~~~
Patients
Sex
PC MS UP AN JJ ME CP AS YN PW GG
M M M M F F F F F F F F
KA M
S.D. Controls (n=5) M S.D.
Age (Y.)
Duration (Y.)
12.6 17.0 17.4 18.2 12.8 13.6 14.2 14.8 14.9 16.7 17.0 17.3 15.5 1.9
1 .o I .o I .o 1 .o 0.8 0.8 1.3 1 .o
0.6
1 .o
3.5 2.5 1.3 0.8
Weight loss (%)
Mean blood pressure (mmHg)
Serumprotein (g/b
27 23 27 23 35 24 15 26 15 31 38 31 26.3 7.0
84 74 80 88 68 84 81 82 76 76 72 82 78.9 5.8
63 68 63 79 72 63 68 74 68 63 64 69 67.8 5.1
97.0 4.0 10.001
70.2 3.4
14.8 0.9 n.s.
P
tein was analyzed with a refractometric method. Blood pressure was measured with a cuff and mean arterial blood pressure calculated as the diastolic pressure plus 40% of the pulse amplitude. Determination of maximal urine osmolality Nine of the patients were deprived of fluid and food for 17 hours starting at 5 o’clock p.m. Two to three urine sam-
n.s.
ples were obtained by spontaneous voiding and used for determination of osrnolality. The fluid deprivation test was repeated, but at this time an intramuscular injection of vasopressin (Pitressin tannate in oil@) in a dose of 0.5 pressor units/6 kg of body weight was given at the start of the fluid deprivation. Two to three urine samples obtained by spontaneous voiding were obtained after 17 hours and analyzed for urea and osmolality.
Table 2 . Renal hemodynamics in patients with A N n.s .=non significant
GFR Patients
I/hour
Ilhour 1.73 m2b.s.
I/hour
I/hour 1.73 m2 b.s.
FF
(%I
3.46 4.09 4.28 4.63 3.16 3.16 4.16 3.13 3.03 2.30 2.92 4.20
4.94 4.30 4.54 4.99 4.52 3.56 5.72 3.64 4.30 3.04 4.01 4.93
25.17 29.20 32.83 27.47 23.11 18.76 20.27 19.22 15.92 17.55 19.17 30.71
35.99 30.61 34.85 28.63 33.04 21.21 28.74 22.33 22.58 22.83 26.32 37.15
13.7 14.0 13.0 16.9 13.7 16.8 20.5 16.4 19.0 13.1 15.2 13.7
3.54 0.71
4.37 0.74
23.28 5.66
28.69 5.71
15.5 2.4
5.77 0.89
6.20 0.56
26.36 1.45
29.26 2.13
21.9 2.8
