Glomerular disorders are relatively uncommon globally; however, they remain the primary cause of chronic kidney disease (CKD) and end-stage renal disease (ESRD).
Glomerular disorders are diseases that affect the filtering ability of the kidneys by damaging filtering units known as the glomeruli.1
These tiny, looping networks of capillaries in the nephron perform one of the key body functions – acting as a primary filtering point for removing waste and excess water from the blood while retaining essential components, such as blood cells and protein, during urine formation.
In glomerular disorders, injuries or insults to these glomeruli can lead to protein and/or blood leaking in the urine. Simultaneously, waste and fluid can build in the bloodstream, eventually progressing to CKD or ESRD if the condition is not well managed.
This heterogeneous group of disorders can start suddenly (acute) or develop gradually over several months as a chronic condition.
They are often considered complex and challenging because the underlying cause is usually unknown or a confirmed diagnosis of a specific type is unavailable at the time of underwriting.
This article aims to strengthen underwriting and claims professionals’ understanding of glomerular disease while demonstrating how RGA’s updated Global Underwriting Manual (GUM) guidelines can support more effective decision-making and enhance the overall user experience.
Broadly, glomerular disorders can be categorized into two groups:2
Based on etiology, immunopathology, or the histological pattern of the disease, glomerular disorders could further be classified as follows:3,4
Off all sub-types, IgA nephropathy, also known as Berger’s disease, is the most common type globally.
Regardless of type of glomerular disorders, the prognosis is largely determined by factors such as blood (hematuria) or protein (proteinuria) in urine and renal function status, including baseline estimated glomerular filtration rate (eGFR) and eGFR trajectory over time.
RGA’s Global Underwriting Manual (GUM) kidney disorders guidelines include a simplified risk classification table. In addition to rating guidelines updates, “refer to MD”-type decisions have been eliminated or replaced with alternative rating decisions, further improving the user experience.
For most glomerular disorders, patients may remain asymptomatic for a considerable period, until the condition progresses. However, general observable symptoms include:7,8
Systemic signs may include skin rashes or joint pain. In advanced cases, patients may develop nausea, loss of appetite, or shortness of breath due to pulmonary edema.
Diagnosis typically begins with urinalysis, kidney function tests, and imaging tests to assess kidney shape and size. Further tests could be necessary, depending on the chronicity and clinical context of the condition, including hepatitis or HIV testing, anti-GBM (glomerular basement membrane) antibodies, antineutrophil cytoplasmic antibody (ANCA) testing, and others.9,10
In cases where diagnosis is uncertain, kidney function is rapidly deteriorating, or immunosuppressive treatment is considered, a kidney biopsy may also be performed to establish the diagnosis.
Treatment usually starts as supportive aimed at controlling blood pressure and urinary findings. For severe cases, dialysis or renal transplantation may be reserved.
Newer therapies – such as sodium-glucose cotransporter-2 (SGLT2) inhibitors, including dapagliflozin and empagliflozin – are increasingly used for their nephroprotective effects. These agents may help slow disease progression by reducing intraglomerular pressure, decreasing proteinuria, and mitigating renal inflammation. Their use depends on the patient’s eGFR and individual tolerability.11
Immunosuppressive therapy may be considered in select patients with active inflammatory forms of glomerulonephritis, depending on the underlying disease subtype, severity, and risk of progression.
The prognosis of glomerular disorders, including all sub-types, is linked to multiple clinical and histological factors. The key prognostic indicators include baseline renal function, eGFR trajectory over time, proteinuria burden and persistence, hematuria pattern, blood pressure control, treatment response, histological chronicity, and associated systemic disease or comorbidities.12,13
Individuals with the profile below tend to have a better prognosis and should be quick check points for underwriters:
These factors were carefully considered when developing a new risk classification table, which should help underwriters better stratify risk of glomerular disorders of “unspecified types or cause unknown” by categorizing them into various severity classes, ranging from mild to very severe, and applying the updated guidelines effectively.
Even for the most common specified type (IgA nephropathy), a new, simplified risk classification table segregates this condition into low-grade to progressive IgA nephropathy.
As noted, glomerular disorders are a diverse group of conditions, and their impact on mortality and morbidity can vary depending on the specific condition or sub-type.
Mortality from acute glomerulonephritis has improved over the past three decades and is now broadly comparable to that of the healthy general population. This supports favorable risk assessment for acute cases.16
In contrast, chronic glomerulonephritis may carry different mortality risks, depending on the subtype. The table below summarizes mortality across five major types of glomerulonephritis.
As the table demonstrates, while mortality varies among subtypes, insurability does not appear very concerning.
However, across all subtypes, risk dramatically increases when kidney function is significantly impaired, meaning markers are eGFR <60, proteinuria >3 g/day, or systolic blood pressure >140. Under these circumstances, the mortality increase is reported by an additional one-to-two-fold. This demonstrates that renal function markers are critically important factors in glomerulonephritis and should be considered during risk assessment.
Likewise, for living benefits such as critical illness coverage, insurability depends largely on the type of glomerulonephritis, the benefit design, and modifiable factors such as proteinuria, hematuria, and hypertension, as noted under mortality. The risk of cancer or cardiovascular disease events is about 1.5-fold, which is factored in the guidelines.18,19
The impact on disability benefits is significant. Disability may result not only from ESRD or CKD but also from systemic complications such as anemia, metabolic bone disease, and reduced work capacity caused by fatigue, edema, or cognitive slowing.
Globally, age-standardized disability-adjusted life years (DALYs) per 100,000 increased from 78 in 1990 to 85 in 2021, indicating that the global burden of glomerulonephritis-CKD is increasing and remains a significant challenge.20 This varies across age and gender and may be linked to a lack of healthcare facilities and the condition’s chronicity. However, DALYs are expected to improve over time, owing to the healthcare accessibility, early diagnosis, and effective treatment/management of the respective disorder type.
Data for chronic glomerulonephritis with regard to mortality or morbidity is limited, with many studies including only a small number of cases. Results may vary by subtype and study design; therefore, the outcomes from such research should be viewed as general guidance. Insurability is best determined through a risk-based evaluation of core prognostic indicators, enabling underwriters to differentiate stable, well-controlled cases from those with higher potential for adverse outcomes.
With updated guidelines, milder forms of the disorder now can be risk assessed with improved terms while severe types can be handled conservatively based on the risk presented. Living benefits may now be considered in selected cases with appropriate caution, rather than being declined outright.
Glomerular disorders include many rare and varied subtypes, which makes it difficult for underwriters to be fully familiar with each disease pattern, expected outcome, and clinical implication. This can make risk assessment challenging, particularly when the exact subtype is not known or when the available medical information is limited.
RGA’s updated GUM guidelines address these practical challenges by presenting information in a clearer, more structured manner. By using relevant risk factors, simplified classifications, and competitive guidance for both mortality and morbidity benefits, the guidelines can support more consistent decisions, faster case handling, and an enhanced experience for both underwriters and insurance applicants.
For more details, please reach out to your local RGA representative or connect with us.
