Diabetes insipidus (DI) is a rare condition, however, it is often confused as Diabetes
Mellitus despite being completely different conditions. Diabetes Mellitus is commonly referred
to as “Diabetes”, and many people do not know the differences between these similar-sounding
conditions (Levy et al., 2019). Diabetes Mellitus is characterized by either insulin resistance or
inadequate insulin production resulting in unregulated blood glucose levels (Perkins, 2020).
Whereas diabetes insipidus has no connection with blood glucose at all (Perkins, 2020).
Diabetes mellitus and diabetes insipidus both involve symptoms of polyuria and polydipsia but
that is where the similarities end (Perkins, 2020).
The etiology of diabetes insipidus is multivariate as there are four distinct types: central,
Nephronergic, Dipsogenic, and Gestational (Levy et al., 2019). Central DIs are the most common
form and are characterized by dysfunction of the hypothalamus or pituitary resulting in a
deficiency of antidiuretic hormone and thus decreasing reabsorption of water in the
nephron(Perkins, 2020). Nephrogenic DI is associated with decreased reabsorption of water in
the distal convoluted tubule and collecting ducts due to vasopressin insensitivity(Perkins, 2020).
The mechanism of Dipsogenic DI is not clearly understood, however, it is not related to ADH or
vasopressin levels and is associated with the hypothalamic defect (Perkins, 2020). And lastly,
gestation DI is associated with the third trimester of pregnancy (Perkins, 2020). Vassopressinase
created by the placenta inhibits the mother's vasopressin, thus creating a temporary diuresis
effect that resolves 3 weeks after delivery (Perkins, 2020).
Nephrogenic DI is of particular interest due to its potential drug interactions with some
medications. However, it is thought that polypharmacy involving medications that impact renal
function may be associated with Nephrogenic DI (Erden et al., 2013). Lithium particularly has
been shown in the literature to have a direct correlation to the onset of nephrogenic DI which is a
key finding due to its high prescription rate for treatment of various mood disorders (Erden et al.,
2013).
Diabetes Insipidus is similar In syntax but fundamentally different from diabetes
Mellitus, and it is imperative to understand the differences so they can be treated effectively.
References
Erden, A., Karagöz, H., Başak, M., Karahan, S., Cetinkaya, A., Avci, D., & Bugǧday, I. (2013).
Lithium intoxication and nephrogenic diabetes insipidus: a case report and review of
literature. International journal of general medicine, 6, 535–539.
https://doi.org/10.2147/IJGM.S46383
Levy, M., Prentice, M., & Wass, J. (2019). Diabetes insipidus. BMJ, 364.
https://doi.org/10.1136/BMJ.L321
Perkins, A. (2020). Diabetes insipidus. Nursing Made Incredibly Easy!, 18 (3), 28-37. doi:
10.1097/01.NME.0000658172.72738.c2.