1. A Sugar Tolerance test gives information of great
value for the accurate diagnosis and treatment of
an obese patient.
2. About 25% of obese subjects show a response to
the glucose tolerance test indistinguishable from
that found in a definite case of diabetes mellitus.
Such cases, though not as yet showing the characteristic
clinical signs of diabetes, should be
regarded as mild diabetics and treated as such.
If left untreated they will, in all probability,
ultimately become true diabetics.
3. A small proportion of obese cases are the result
of an Endocrinopathy, e.g. Fröhlich's syndrome,
"post -pregnant" obesity (from exhaustion of the
thyroid). The blood sugar shows a poor response'.
to the glucose tolerance test, and the probable
cause of the laying on of fat is the fat sparing
action of the carbohydrate of the food.
4. There is a second type of obesity in which decreased
sugar tolerance is a prominent feature.
It again may be sub-divided into two groups.
The 1st Group is characterised by obesity,
high blood pressure, hyperglycaemia, and evidences
of Renal impairment. The blood sugar curve is
exaggerated and prolonged; there is no glycosuria
associated, this being due to a raised renal
threshold (probably a result of chronic interstitial
The 2nd Group is the "Essential Hypertonias"
characterised by arteriosclerosis, hypertension,
obesity, and hyperglycaemia. They differ from the
above group in having no evidence of Kidney involvement.
They show a fasting hyperglycaemia.
Both types probably admit of a common explanation
and both show evidence of impaired carbohydrate
metabolism. Their relation to the "pre - diabetic" Group III is as yet uncertain. Their
relation to diabetes mellitus seem to be more
distant than that of the above Group III. This
group with hypertension and nephritis, or hypertension
and arteriosclerosis, associated with
hyperglycaemia and obesity, probably includes
about 10% of all cases of Obesity.
5. About 60-70% of Obese subjects have a comparatively
normal blood sugar concentration, and respond in a
normal manner to the sugar tolerance test. The
obesity in such cases is probably due to a simple
disproportion between energy intake and expenditure.
6. It is possible that the above type of case may
progress until hypertension, nephritis, arteriosclerosis
start their vicious circles, and force.
the case into Group II.