THE SIGNIFICANCE AND DETECTION OF< 
SUGAR IN THE URINE, 
WITH SOME REFERENCE TO 
LIFE INSURANCE. 
BY 
GEO. B. FOWLER, M. D., 
PROF CLINICAL MEDICINE AND MEDICAL CHEMISTRY, N. Y. POST GRADUATE 
MEDICAL SCHOOl, VISITING PHYSICIAN TO BELLEVUE HOSPITAL 
AND THE NEW YORK INFANT ASYLUM. 
Reprinted from The Dietetic Gazette, October, 1888. 
NEW YORK: 
“The Hub” Press, 39-43 Gold St. 
1888. THE SIGNIFICANCE AND DETECTION OF 
SUGAR IN THE URINE, 
With some Reference to Life Insurance. 
GEO. B. FOWLER, M. D. 
The materials introduced into the body for its main- 
tenance are the albuminoids, carbo-hydrates, hydro- 
carbons, salts, water, and oxygen. The substances 
which, under physiological conditions, appear in the 
excretions are, practically speaking, urea, salts, car- 
bonic acid, and water. The albuminous matters serve 
their purpose, and, being non-diffusible, are converted 
into the crystaloid urea in order to be gotten rid of. 
The carbo-hydrates and hydro-carbons, having a great 
affinity for oxygen, are by this agent converted into 
water and carbonic acid; while the remaining proxi- 
mate principles, the mineral salts and water, being 
very diffusible and little prone to change, are excreted 
under their own forms. Thus, theoretically, at the 
start it appears that, under normal conditions, the 
urine should contain none of the organic ingredients 4 
of the food, nor any of their immediate derivatives 
[Albumen, peptone, paraglobulin, metalbumen, glucose, 
maltose, chyle.] 
On the other hand, various observers have for many 
years held that sugar is a natural ingredient of the urine 
[Bince Jones, Briicke, Brodecker, Gubler, Pavy], while 
as many equally reliable ones have failed to satisfy them- 
selves of its presence. [Lehman : “ Physiological Chem- 
istry,” Phila., 1855, Vol. 1, p. 257; Kulz, Malay, See- 
gen, Gorup-Besanez.] Thus has arisen a controversy 
which I think, however, is now about concluded. Those 
who maintain the affirmative of this question have 
either been obliged to employ large quantities of urine, 
concentrate it by evaporation, and bring to bear pro- 
found chemical knowledge in order to demonstrate a 
trace of sugar, or they have depended upon the re- 
ducing properties which normal urine possesses when 
treated with some of the standard tests for glucose. 
Now, normal urine which will respond to the reduc- 
tion tests, will not undergo the alcoholic fermentation 
in the presence of yeast. And it is generally acknowl- 
edged by those who consider sugar to be a normal 
constituent, that urine contains something else capable 
of reducing cupric oxide. Uric acid has long been 
known to possess this property, and Dr. Pavy [“ Med. 
Chir. Soc. Trans.,” Vol. 63, p. 222] expresses his 
side of the question when he says that the re- ducing action (on cupric oxide) which normal urine 
exerts is due, one-fourth to uric acid and three-fourths 
to the small amount of sugar naturally present in the 
urine.* He further adds that it is doubtful if there is 
any other body worthy of consideration which has any 
reducing effect. Our own experiments on this point 
have convinced us that after the removal of the uric 
acid from normal urine by lead acetate, the urine still 
contains something capable of reducing cupric oxide 
and picric acid, yet inactive to the yeast test, even 
when concentrated by evaporation ; and our conclusion 
was that this something is not sugar. Therefore our 
belief has been, and still is, that the urine from a person 
who is free from disease or functional disorder, and 
who has not recently ingested an excess of starchy or 
saccharine food, will be found to be free from sugar. 
This view has been recently verified by the re- 
searches of Mr. George S. Johnson, M. R. C. S., F.C.S., 
etc. [“ Proc. Royal Soc.,” Vol. 42]. In a word, Mr. 
Johnson has discovered that, besides uric acid, which, 
agreeing with Pavy, represents one-fourth the reducing 
action of normal urine, there is another body, not 
sugar, which answers for the other three-fourths, 
namely, kreatinin. And that when both the kreatinin 
5 
*Dr. George Johnson, in an analysis of 300specimens of urine, found a 
reducin'; substance which reacted with copper and picric acid, but not 
with yeast —Lancet, June, 1883. 6 
and uric acid are removed, the final filtrate has no re- 
ducing effect either with cupric oxide or picric acid. 
And as uric acid does not reduce picric acid, Mr. 
Johnson has discovered that it is kreatinin which 
causes all urines to react with this test. 
The conclusions of this observer are that “ cupric 
oxide will be reduced by the normal urine in quanti- 
ties equivalent to the reduction effected by 0.43 to 
0.51 grains of glucose per 1 fluid ounce. The total 
reduction effected by normal urine is accounted for by 
the uric acid and kreatinin which it contains.” * And 
Dr. George Johnson, basing his faith upon his son’s 
researches, says [“Brit. Med. Jour.,” Jan. 8, 1887] that 
it is conclusively proven 
1st, That not a trace of sugar is to be found in 
normal urine. 
2d, That as uric acid has no reducing action on 
picric acid, the chief, if not the sole, con- 
stituent of normal urine which reduces picric 
acid in the presence of potash is kreatinin. 
From what we have said regarding our position on 
the question as to the presence of sugar in normal 
urine, it is evident that the researches and conclusions 
*Mr. Johnson mentions that “ uric acid and kreatinin together are 
credited by Prof. E. Salkowski- [“ Cent. f. d. Med. VViss’sch’n,” March, 
1886] with one-sixth to one-fifth of the total reducing action of normal 
urine, the remainder being due to “ other substances, and very prob- 
ably to compounds of glycuronic acid [Glykuronsauereverbindingen].” 7 
just described were of great interest to us, and we im- 
mediately set to work to repeat the experiments. 
The result is that we are perfectly satisfied as to 
their correctness, and feel justified in believing that 
the verdict must stand: Normal urine contains no 
sugar. 
Hence the presence of sugar in the urine in any 
amount must have some significance, and it behooves 
us to familiarize ourselves with all possible conditions 
with which it is associated, in order to determine its 
import. 
To begin with, we would have the distinction be- 
tween glycosuria and diabetes mellitus constantly 
borne in mind. Too many writers confound the terms. 
We may have glycosuria without the diabetic element, 
as we may have diabetes without the glycosuric 
feature. Without going into the complicated and un- 
settled pathology of glycosuria, with or without dia- 
betes, we will state that our understanding and belief 
is that diabetes mellitus is the result of a central 
lesion of the nervous system, while glycosuria is 
caused by direct irritation of the hepatic vessels by 
toxic constituents of the blood. [Pavy, Harley, Ralf.] 
We believe that Prout [“ Stomach and Renal Dis- 
eases,” Phila., 1843, P-431 was the first to describe cases 
of glycosuria without diabetes, occurring in gout, dys- 
pepsia and in the aged. He also points out the fact 8 
that a low specific gravity of the urine is no certain 
indication of the absence of sugar. The extremes 
of specific gravity which he encountered ranged 
from 1020 to 1050, and once or twice he had seen 
it at 1013; and in a note he records an instance 
where it was 1010 and distinctly and rapidly under- 
went the vinous fermentation. Seegen and others, 
ourselves included, have since frequently found 
sugar in urines of low specific gravity. 
Dr. Wm. Ord [“St. Thomas’Hosp. Report,” Vol. 
XII., p. 1] in a paper on “Some Clinical Aspects of 
Glycosuria,” narrates a series of cases wherein the 
urine contained sugar in variable amounts, unasso- 
ciated with the diabetic element. Many proved to be 
of a serious nature, and at times the presence of sugar 
was difficult to detect. His list, which excludes tem- 
porary glycosuria “ from certain passing provocations,” 
consists of twenty-two cases, ranging from fifty to 
eighty-four years of age, and includes only two 
women. There were twenty cases of nervous dis- 
orders ; gout, eight; errors of diet, over-eating and 
drinking, three; albuminuria, ten. There were two 
cases of syphilis in young persons, with variable 
amounts of sugar. The conditions found to exist and 
symptoms complained of were nervousness, excessive 
mental work, anxiety, insanity, apoplexy, locomotor- 
ataxia, hypochondriasis, tinitus, shingles, hysteria, 9 
headache, loss of memory, numbness in limbs, sciatica, 
and angina pectoris, two cases. 
We have notes of twelve cases bearing upon this 
subject, of which the following four are good exam- 
ples : 
1. L. W., age 35, upholsterer. Has felt ill for a year. 
Lost flesh. Is deoressed and indisposed to work. Has occip- 
ital headache. Bowels regular. Appetite fair. Does not 
drink to excess. Looks pale and tired. Has backache. 
Voids the normal amount of urine Drinks very little water. 
No cause for these symptoms could be discovered by physi- 
cal examination, until we came to the urine. Sp. gr. 1020. 
No deposit. Careful manipulation detected decided trace of 
sugar. Ordered mineral acids and calomel, and to avoid 
sweets and starches. At the expiration of three weeks the 
sugar permanently disappeared, and the patient ceased to 
complain. 
This was a case of faulty tissue metabolism, and he could 
not tolerate sugar. 
2. H., broker in Wall street. Single; 40; 150 pounds; 5 
feet 6 x/i inches. High liver. Drinks to excess. Well until 
recently, when his head began to trouble him. Could not 
apply himself to business. Insomnia. Pain in occiput. Rest- 
less and apprehensive. Does not void an excess of urine. 
Urine, dark amber. Sp. gr. 1015. No albumen Sugar, a 
trace., 
Advised a regular life, abstinence in eating and drinking, 
vacation in the mountains. A month afterwards he was feel- 
ing slightly better, but albumen and renal epithelium had ap- 
peared in the urine. This case has gradually gone on to chronic 
Bright’s. 10 
3. B., 36, 135'pounds, 5 feet 7 inches. Tutor in college. 
Applied for life insurance. Feeling perfectly well. Rarely ill. 
The urine was sent to me for analysis. Daily quantity, 50 § . 
Sp. gr. 1025. A marked trace of sugar. A second specimen 
two weeks later showed sp. gr. 1035, and gave unmistakable 
evidence of sugar with the copper test, but not with fermenta- 
tion. A third specimen two weeks later showed sp. gr. 1030, 
and same chemical reactions as the others. The subsequent 
history of the case I have not been able to learn. 
4. Mr. X., 35, 5 feet inches, 180 pounds. Family his- 
tory excellent. This is a very wealthy gentleman, who carries 
a large line of life insurance, and desired to increase it. 
He has scarcely ever known a sick day, is genial, and in ap- 
pearance is in'perfect health. He had never encountered any 
difficulty in being accepted by any company until last winter, 
when his urine, being examined by a very competent physi- 
cian for an out-of-town company, showed a sp. gr. of 1026, and 
with Fehling’s solution it gave a prompt and copious deposit of 
cuprous oxide This discovery surprised the physician and 
startled the gentleman. The risk was postponed, and Mr. X. 
was unable to obtain the additional insurance which he desired. 
The case was referred to the writer. No other evi- 
dence of disease could be found. The patient felt 
perfectly well, and was not aware of an ache or pain. 
The only thing observed about him was an intense and 
nervous manner. Nine specimens of his urine were 
examined, voided at various times of day, and under 
conditions both of abstinence and while indulging in 
an excess of sweets. The daily quantity was never 
excessive, but the specific gravity always ranged be- 11 
tween .1025 and 1030, and in every instance unmis- 
takable evidences of sugar were present. These facts 
were stated to the various life insurance cOrrfpanies 
with whom the gentleman wished to insure, and the 
result was that some declined, while others accepted 
him for large amounts. So far as known he continues 
to enjoy good health. 
Now, enough has been said to indicate the points 
which we wish to make prominent regarding the sig- 
nificance of small amounts of sugar in the urine. Of 
course, we do not mean those instances familiar to us 
all as being insignificant, which are associated with 
what Dr. Ord calls “ passing causes,” and constituting 
temporary glycosuria. Such conditions are easily 
produced by the rapid absorption of an excess of 
starchy or saccharine food, slight nervous derange- 
ments, physical exercise, etc. We speak of cases 
where a trace of sugar is either constantly or inter- 
mittently found in a given urine, unassociated with 
the diabetic element, and associated or not with ascer- 
tainable bodily ills. The life insurance companies are 
not agreed whether to accept such lives. Formerly 
they would not have considered them for a moment; 
now, however, influenced by a more liberal standard, 
and under the stress of competition, some of the best 
institutions do not hesitate to insure them. 
Of course we do not consider it proved that every 12 
case of even long-standing glycosuria indicates an in- 
curable derangement. For we have seen how often 
it is a part of the general disorders which we call gout, 
dyspepsia, neurasthenia, etc. Yet we do hold that we 
should bear in mind its equally frequent connection 
with serious and fatal affections of the brain, the kid- 
neys and the heart. As it is not true that every case of 
albuminuria means Bright’s disease, so traces of sugar 
in the urine do not indicate diabetes mellitus. Yet, as 
the discovery of a trace of albumen in the urine means 
look out! so the finding of a small quantity of 
sugar indicates danger. The thought often occurs to 
us whether the heavy mortality which life companies 
often experience among those whose applications 
present the cleanest records of personal health and 
family history may not, in part at least, be due to the 
failure of the examining physician either to appreciate 
the significance of the subject which we are discussing, 
or to be able to apply the proper tests to discover it. 
A man who has a serious chronic disease, as a rule 
suddenly develops an insatiable desire to have his life 
insured. Agents whom hitherto he would not recog- 
nize even in church, and against whose approaches he 
had always provided an impregnable barricade, now be- 
come his bosom friends and confidential advisers. 
They get at his symptoms with a skill all their own. 
They find that the disease is glycosuria, for instance. 13 
The patient is immediately advised to live strictly ac- 
cording to orders as to diet, etc., and is shown how to 
submit his urine to the specific gravity test and Feh- 
ling’s solution every morning. Pretty soon a specimen 
is encountered which is not suspicious, and with this 
in his pocket application for insurance is made to 
some company known to be not over-skillful in their 
examinations. That such risks frequently pass we very 
well know. 
Although it is a simple matter to demonstrate the 
presence of sugar in the urine of a case of established 
diabetes mellitus, it is not so easy to detect a trace in 
instances where the diabetic element is absent. In the 
former case the urine is highly diluted wfith water and 
loaded with sugar, while in the latter the proportions 
of the normal constituents of this fluid are very little, 
if at all, altered. On several other occasions we have 
drawn attention to the fallacies and interferences 
which the natural urine offers towards the usual tests 
for sugar, especially if present in minute proportions. 
[“Detection of Sugar in Urine,” N. Y. Med. Jour., 
Sept., 1872 ; “Note on the Detection of Sugar in 
Urine,” N. Y. Med. Record, May 2, 1885.] 
Of all the tests which are known to possess charac- 
teristic reactions with glucose, a few only are ap- 
plicable to the urine under conditions convenient, 
satisfactory and comprehensive to the practising phy- 14 
sician. These are Fermentation, Trommer’s (or Feh- 
ling’s modification), and the Bismuth test. 
The most convenient method for the application of 
the fermentation test is Einhorn’s saccharometer,* 
which is probably familiar to most of us. It consists 
of a tube bent upon itself, one arm being short and 
dilated so as to form a bulb. The upright tube col- 
lects the gas, and is graduated so as to read from >4 
to 1 per cent., or from 1 to 5 C. C. In experimenting 
with this apparatus with solutions of glucose of known 
strength the amount of gas collected did not agree 
with the graduations, and were different for the same 
solution with different trials. Hence we cannot de- 
pend very much on fermentation, and this instrument 
especially, for an accurate quantitative analysis of 
saccharine solutions. This is especially true when we 
are dealing with organic fluids. The urine, for 
instance, will absorb its own volume of carbonic acid 
gas at the ordinary temperature, and will vary in this 
regard according to the degree of its alkalinity or 
acidity. We have frequently discovered an appreciable 
amou'nt of sugar by the copper test in urine, which 
failed to evolve a bubble of gas when treated with 
yeast. Then, again, sugar in contact with nitrogenous 
substances, at an elevated temperature, is apt to be 
*Can be obtained at Eimer & Amend’s, Third Avenue and Eigh 
teenth Street, and directions accompany it. 15 
converted into lactic acid, and thus disappear. The 
fermentation test is, therefore, not a very delicate one, 
failing in my hands to demonstrate one-tenth of one 
per cent, of sugar, and, consequently, must not be 
relied upon where great delicacy is demanded. It is, 
however, very useful and simple under ordinary circum- 
stances. 
When it is desired to detect minute proportions of 
sugar with Fehling’s solution, the urine should be 
filtered through animal charcoal (a paste being made) 
by which decoloration is effected, and the Fehling 
should be deprived of its intense blue color by dilu- 
tion, about one-half, with distilled water; with these 
conditions small degrees of reduction become visible. 
After .boiling, which should be only for a moment, it 
is important to set the test-tube aside for an hour, and 
then scrutinize the bottom of it for any granules of 
red copper oxide which may not have been seen in 
suspension, but which have now settled down. 
Another metal whose salts suffer spontaneous 
reduction by glucose, in a boiling alkaline solution, is 
bismuth. A solution analogous to Fehling’s is thus 
made: 
10$ Sol. Sodium Carb too. 
Bismuth Subuit 2. 
Rochelle Salts 4. 
M 
Use one part of this to ten of urine; boil, and, if 16 
sugar is present, the whole assumes a gray or black 
appearance, due to the reduction above spoken of. 
The conclusions which we would submit are the fol- 
lowing : 
1. Normal urine contains no sugar. 
2. The reducing power of normal urine upon cupric 
oxide and picric acid is due to uric acid X and krea- 
tinin X- Both these bodies are removed by adding 
to the unconcentrated urine one-twentieth its volume 
of a cold saturated solution of sodic acetate, and 
then one-fourth its volume of a cold saturated solution 
of mercuric chloride, after the manner described by 
Johnson. 
3. Any reduction of either cupric oxide or picric 
acid after this manipulation is due to the presence of 
sugar. 
4. Sugar may persist in traces, unaccompanied by 
the diabetic element. 
5. Diabetes may be warded off by recognition of the 
first appearancesugar as a persistent ingredient of 
the urine. 
6. The importance of this subject to life insurance 
companies, in view of the facts above stated. 
7. The detection of traces of sugar in the urine 
requires special skill and care, and a low specific 
gravity should not be considered conclusive evidence 
of the absence of sugar.