A 96 year old lady, seeing her Family Doctor. Clinical information is
'Diabetic'. Serum results were

Sodium:	140 mmol/L
Potassium:	4.1 mmol/L
Urea:		7.7 mmol/L	(2.8 - 7.0)
Creatinine:	88 umol/L	
Albumin:	36 g/L
Adjusted calcium:	2.72 mmol/L	(2.10 - 2.55)
Phosphate:	0.83 mmol/L	(0.81 - 1.45)
Cholesterol:	3.8 mmol/L
Triglycerides:	1.1 mmol/L	
Uric acid:	246 umol/L
Free T4:	22.9 pmol/L	(10 - 26)
TSH:		<0.1 U/L	(0.25 - 5.5)

This Case provoked 41 replies. There were clearly three strands of concern,
but interestingly very few participants mentioned all three. There was one
minor, and one very major disagreement among the assessors (indicated with
asterisks below). For the comment 'further investigation at this age may be
inappropriate or better discussed ' two assessors gave +2, and two -2
(however one of the latter said 'I hope it's not my grandmother). My
sympathies are mainly with the +2s - see my comment below.

A. High calcium
16 participants would suggest a PTH measurement [1.0]
11 would ask for a repeat calcium and phosphate (fasting and uncuffed)
[1.2]
3 would suggest protein electrophoresis [1.0]
2 would measure alkaline phosphatase [0.6*]

14 queried hyperparathyroidism or other malignancy [1.6]
4 said that the calcium may be related to hyperthyroidism [-0.4]
1 queried osteomalcia.[-1.4]

B. Low TSH
14 participants would add a free T3 measurement [1.4]
3 participants would suggest repeating the thyroid function tests [0.4]
1 participant would suggest thyroid antibodies [-1.0]
1 would check for possible assay interferences [0.4]

8 queried whether the patient was on thyroxine replacement [1.2]
4 suggested over-replacement [0.4]
4 specifically queried hyperthyroidism [0.6]
8 said that the low TSH was probably of no consequence at this age. [-0.6]
2 queried non-thyroidal illness. [0.0]
2 mentioned the (remote) possibility of multiple endocrine neoplasia.
[-1.0]

C. Age
6 participants said that at this age further investigation may be
inappropriate or further discussed with the clinician [0.2*]
2 participants mentioned that cholesterol/ lipid investigations are
inappropriate at this age; [1.6]
2 queried why glucose had not been measured. [0.6]
1 said that results look too healthy for a 96 year old diabetic.

We had no previous investigations listed on this patient, so I do not know
when she might have been diagnosed as being diabetic. The request for
'fasting lipids' was I suspect driven by protocol in the Family Doctor's
Diabetic Clinic, the protocol probably not mentioning the age of the
patient. Glycated haemoglobin was requested with this sample, but no
suitable sample was received. There was no evidence of previous requests
for thyroid function tests, so I guess that this lady was probably not on
thyroid replacement. However, I have come across several similar sets of
thyroid results on patients of this sort of age, an added T3 has always
been within reference limits, and I have never known what to make of them. 

Had this lady been twenty years younger, I would have added a free T3, and
suggested a repeat calcium with phosphate and perhaps a PTH. But in this
Case, my comment was the rather cautious

'Slightly raised calcium - cause? Suppressed TSH is of doubtful
significance at this age - are there any symptoms of hyperthyroidism?' 

thus throwing the onus back on the Family Doctor whether to investigate the
patient further (so far, he hasn't).

Best wishes
Gordon Challand


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