A 62-year-old man sought medical
attention at this hospital because of general malaise, limbs
weakness, and nausea for half a month. He had chronic
obstructive pulmonary disease (COPD) but had poor drug
compliance. He often developed intermittent dyspnea and
visited local clinics for treatment. He was noted to have
progressive facial swelling and obesity, and then, he stopped
medications by himself. One month prior to this admission, he
experienced general malaise, fatigue and nausea gradually. He
denied having hemiparesis, dysarthria, easy chocking, an
unstable gait, or stool or urine incontinence. There was
neither epigastric pain nor diarrhea. Because of the above
symptoms, adrenal insufficiency or hypothyroidism was
suspected. A test of serum cortisol level in the morning
showed a relatively low level of cortisol (8.2 μg/dL). Thyroid
functions were within normal limits. Throughout his whole
disease course, there was no visual deficit, headache, joint
pain or paresthesis. He did not consume alcohol, undergo
operation or have a family history of endocrine disorders.
On physical examination, his
consciousness was clear, height was 168 cm and weight was 80
kg. The body temperature was 36.8°C, pulse rate was 72 beats
per minute, respiratory rate was 20 breaths per minute, and
the blood pressure was 126/80 mmHg. Moon face, plethora,
buffalo hump, central obesity with abdominal striae was noted.
There was supraclavicular fat pad and thin skin with easy
ecchymosis. The conjunctivae were pink, sclerae were anicteric
and the pupils were isocoric with prompt light reflex. The
neck was supple without a goiter, palpable masses, engorged
jugular veins or lymphadenopathy. Neurological examinations
were unremarkable.
< Laboratory data
>
1. Hemogram
WBC |
RBC |
HB |
HCT |
MCV |
MCHC |
PLT |
K/μL |
M/μL |
g/dL |
% |
fL |
g/dL |
K/μL |
11.98 |
4.1 |
13 |
37.0 |
89.4 |
34.8 |
189 |
2. Biochemistries and electrolytes
ALB |
TP |
T-Bil |
AST |
ALT |
ALP |
γ-GT |
Glucose |
g/dL |
g/dL |
mg/dL |
U/L |
U/L |
U/L |
U/L |
mg/dL |
3.4 |
6.2 |
0.6 |
33 |
36 |
152 |
17 |
103 |
UN |
CRE |
Na |
K |
Ca |
Mg |
P |
CRP |
mg/dL |
mg/dL |
mmol/L |
mmol/L |
mg/dL |
mmol/L |
mg/dL |
mg/dL |
14.2 |
0.7 |
139 |
3.7 |
8.8 |
0.92 |
3.1 |
<0.8 |
3. Results of endocrinologic
studies
hsTSH |
Free T4 |
ACTH |
Cortisol |
0.4- 4 IU/mL |
0.60-1.75 ng/dL |
10-65 pg/mL |
5-25μg/dL |
0.68 |
1.56 |
12 |
8.2 |
4. The ACTH stimulation test
(250μg synthetic ACTH intravenous
injection)
|
ACTH |
Cortisol |
|
10-65 pg/mL |
5-25 g/dL |
0’ |
12 |
8.2 |
60’ |
11 |
13.4 |
< Course and
treatment
>
After
admission, the ACTH stimulation test with 250μg synthetic ACTH
injection was performed which yielded a relatively low serum
cortisol level (13.4 μg/dl). Under the diagnosis of iatrogenic
adrenal insufficiency, physiological dosage of steroid with
cortisone acetate at a daily dose of 37.5 mg was given. The
symptoms improved gradually. Steroid dosage was tapered
according to clinical symptoms of the patient. After he
deferred one daily dose of steroid, morning cortisol on the
next day showed 16 μg/dL and serum cortisol was within normal
range (26 μg/dL) after ACTH stimulation test. Steroid
replacement was continued. The patient had no significant
discomfort after subsequent withdrawal of steroid replacement.
< Discussion
>
腎上腺功能不足的症狀可輕可重,輕者表現無力倦怠、噁心嘔吐等胃腸道症狀;重者會低血糖、低血壓甚至休克。腎上腺功能不足的原因很多,可以是原發性的,
也可以是次發性的。原發性腎上腺不足最常見是因自體免疫所引起;其次,諸如:腎上腺的結核菌、病毐、黴菌感染及出血等等也會導致功能不足。至於次發性腎上腺功能不足,除了腦垂體或下視丘出問題以外,醫源性
(如:服用類固醇)造成的次發性腎上腺功能不足也是一大原因。這類情形多可藉由藥物史得到蛛絲馬跡。一般而言,類固醇的服用若是以下的情況,皆有可能因類固醇藥物抑制上游腦下垂體而間接對腎上腺造成抑制:
(1)、長久服用卻突然停藥者;(2)、頻繁的短期類固醇療程者
(如氣喘多次發作而常間歇性服用者);(3)、服用類固醇生理劑量超過3週以上者
(但劑量並非絕對)。此類病患往往因長期類固醇藥物而造成類似腎上腺功能過高的庫欣氏症狀群 ( Cushing
syndrome)外觀,諸如:月亮臉(moon face)、臉色紅潤 (plethora)、水牛肩(buffalo
hump)、鎖骨上脂肪墊(supraclavicular fat pad)、肚子暗紅紋路 (abdominal
striae)、薄而脆弱的皮膚及易淤血的體質。然而,實際上身體的腎上腺功能卻顯現為功能不足的狀態。而若有上述服用情形或臨床症狀高度懷疑腎上腺功能不足者,便不能貿然停藥。此時須停用原口服或點滴注射的類固醇至少12-24小時,然後作基礎的早晨腎上腺皮質素濃度測量及皮質刺激素激發測試
(ACTH stimulation test)。若基礎早晨腎上腺皮質素濃度可達10
μg/dL或激發測試後的皮質素濃度可到18-19
μg/dL時,多半表示病人的腎上腺功能尚在可容許的範圍,而可以馬上直接停藥。但若濃度不能達到,表示腎上腺功能可能已受抑制,則須要繼續服用補充類固醇
(多半須要6-9個月的時間,等待腎上腺功能回復),於爾後再慢慢調低類固醇劑量,於較低劑量時再進行如上測試來決定是否可停藥。一般而言,醫源性的腎上腺功能不足為次發性腎上腺功能不足,
故相較原發性功能不足者而言,較不會伴隨低鈉高鉀等電解質不平衡的情況,也不會有皮膚色素增加
(hyperpigmentation) 出現。
< References
>
-
Dixon RB, Christy NP. On the various forms
of the corticosteroid withdrawal syndrome. Am J Med 1980;
68:224-30
-
Byyny RL. Withdrawal from glucocorticoid
therpy. N Engl J Med 1976;295:30-32.
-
Williams textbook of endocrinology, the 10th
edition.
|