Intended for healthcare professionals

Rapid response to:


Establishing a standard definition for child overweight and obesity worldwide: international survey

BMJ 2000; 320 doi: (Published 06 May 2000) Cite this as: BMJ 2000;320:1240

Rapid Response:

Diabetes mellitus and global climate change

To the Editor: The impending global climate change would adversely
affect innumerable patients of diabetes mellitus globally. The climate
change would interfere with diagnostic techniques and therapeutic
interventions. Insulin, the sheet anchor of therapeutic intervention, has
to be stored in powered form at -20oC and in injection form at 2-8oC. To
maintain biological activity, injections have never to be frozen during
storage1. Furthermore, oral hypoglycemic, suplhonylureas and biguanids are
to be stored in controlled temperature of 15 to 25 or 30oC. Any
inadvertent exposure to higher temperatures or accidental freezing could
be disastrous for insulin potency.
A new record for global temperature was established during July 1998 when
the average global temperature reached was 15.5oC, while July 1998 was the
hottest month in past 120 years2. High temperature if accompanied by high
humidity would involve enormous heat transmission to insulin and oral
antidiabetic preparations prescribed for patients with diabetes mellitus.
During the 1995 heat wave in Chicago, the maximum temperature reached was
40oC, but the heat-index, an estimate of radiative and evaporative
transfer of heat was 48.3oC3. Moreover, in developing countries, poor
electricity supplies that disrupt the working of appliances designed to
maintain temperatures at appropriate level4, accompany heat waves.
Furthermore, wars, civil unrest, and natural distress disrupt power
generation facilities in large metropolitan towns for a long period5.
Insulin injections with a mandate to be never frozen and like the vials of
hepatitis B vaccine might be frozen accidentally. In the Northern
territory of Australia, continuous monitoring of 144 vaccine vials
unveiled that during transport to various immunization centers, 47.5%
vials had been exposed to temperature of -3oC or lower6. Similar handling
could be possible with insulin also. Potency of oral hypoglycemic agents,
with desired temperature maxima of 25 or 30oC, might also resemble the
data on potency of assay on other therapeutics with identical storage
temperature requirements.
During the assay of field samples of chloroquine, amoxycillin,
tetracycline, cotrimoxozole and ampiclox in Nigeria and Thailand, 36.5%
samples were found to be substandard. Moreover, in six samples of
chloroquine, there was no active ingredient left7. The scourge of poor
quality antidiabetic therapeutics needs attention by quantification of
field samples for active ingredients and their stabilization against
adverse environment.
Addition of trehalose, pirodavir or deuterium oxide to labile vaccines
stabilized the formulation against high temperature8. An identical
strategy would be useful for insulin and oral antidiabetics Distinctive
symbols have been mandatory for inflammables, poisons and radioactive
substances. It would be desirable to insist for distinctive marks on
vials or tablets to indicate storage requirements about temperature and
humidity. Furthermore, simple tests that do not require costly equipment
or trained personnel would be needed to quantify active ingredient of
insulin, suphlonylurea or biguanid in physicians' premises itself.
High and low ambient temperatures modify the assay data on blood glucose.
A glucose load in a tolerance test is associated with different mean
adjusted glucose concentration at a high or low ambient temperature. A 75g
load of glucose in 1030 pregnant women led to 0.20 mmol/L (3.6 mgm %)
higher concentration at 25-31oC than at 20-24oC. The readings at 5-14oC
were 1.03 mmol/ L (18.6 mgm%) lower than at 25-31oC9. Temperature,
humidity, light and altitude 10 also affect the performance of blood
glucose monitors frequently used to quantify glucose in home rather than
Future effect of global climate warming and the El Niño effect on blood
glucose assay would be minimized after a comprehensive evaluation on the
inimical effects of temperature, humidity, sunlight and altitude on
different parameters. The conventional assays performed in laboratories
and in home with portable glucose meters10 should be meticulously
evaluated to ensure the data on glucose estimates samples were accurate
and precise. An well-integrated approach to ensure availability of potent
therapeutic agents as well as sensitive and specific test for glucose
level would indeed ensure that the harmful effects of climate change would
be countered effectively. Vast magnitude of diabetics all over the globe
need not suffer due to cryptic effects of environment on potency of anti-
diabetic therapeutics r efficacy of glucose quantification technology
available locally.

Subhash C Arya
Centre for Logistical Research and Innovation
M-122 (of part 2), Greater Kailash-II
New Delhi- 110048, India


1. Physicians' Desk Reference. 53rd edition. Medical Economics
Company. Montvale, 1999

2. United States Environmental Protection Agency. Global warming.
Vice President Gore announces new data showing that July 1998 was the
hottest month on record. August 10, 1998

3. Heat-related mortality- Chicago, July 1998. MMWR 1995; 44: 577-579

4. Kumar S. India's heat wave and rains result in massive death toll.
Lancet 1998;351: 1869

5. Horton R. Croatia and Bosnia: the imprints of War-II.
Consequences. Lancet 1999; 1999;353:771

6. Miller NC, Harris MF. Are childhood immunization programmes in
Australia at risk? Bull Wld Hlth Org 1994; 72:401-408

7. Shakoor O, Taylor RB, Behrens RH. Assessment of the incidence of
substandard drugs in developing countries. Trop Med Int Hlth 1997;2:839-

8. In Brown F, editor. New approaches to stabilisation of vaccine
potency. Basel, Karger, 1996

9. Schmidt MI, Matos, Branchtein L, et al. Variation in glucose
tolerance with ambient temperature. Lancet 1994;344:1054-1055

10. Urdang M, Ansede-Luna G, Muller B, et al. An independent pilot
study into the accuracy and reliability of home glucose monitors. Lancet

11. Nichols JH. Laboratory and bedside evaluation of portable glucose
meters: the Author's reply. Am J Clin Path 1995;104:483

Competing interests: No competing interests

26 May 2000
Subhash C Arya