Background: Renal volume (RV) is associated with renal function and with a variety of cardiovascular risk factors (CVRFs). We analysed RV using magnetic resonance imaging (MRI) in a large population-based study (Study of Health in Pomerania; SHIP-TREND) to find sex- and age-specific reference values for RV and to test the influence of several markers on RV. The main objective is to describe reference values for RV in people from the general population without kidney disease. Methods: 1815 participants without kidney disease (930 women) aged 21–81 years were included in our study. Right and left RV with and without body surface area (BSA) indexation were compared among three age groups (22–39 years, 40–59 years, 60–81 years) by median and interquartile range and tested separately in women and men. Results: The estimated glomerular filtration rate (eGFR), serum uric acid, and right and left RV were higher in men compared to women (all p < 0.001). Left kidneys were larger than right kidneys (both sexes). With age, RV showed a continuously decreasing trend in women and an upside-down U-shaped relation in men. In multivariable linear regression models, current smoking (β = 14.96, 95% CI 12.12; 17.79), BSA (β = 97.66, 95% CI 90.4; 104.93), diastolic blood pressure (β = 0.17, 95% CI 0.01; 0.32), and eGFR (β = 0.57, 95% CI 0.50; 0.65) were positively associated with both left and right RV, whereas uric acid (β = −0.03, 95% CI −0.05; −0.01) showed an inverse association with RV. Interestingly, the same eGFR correlated with higher RV in men compared to women. Conclusion: Reference values for RV are different for age groups and sex. For any given age, female kidneys are smaller than male kidneys. RV associates positively with eGFR, but for any chosen eGFR, renal volume in females is lower compared to males. RV decreases with age, but in men showed a U-shaped correlation. This may reflect hyperfiltration and glomerular hypertrophy associated with the presence of CVRF in middle-aged males.

Given the increasing prevalence of chronic kidney disease (CKD) and its impact on health care, it is important to better understand the multiple factors influencing health-related quality of life (HRQOL), particularly since they have been shown to affect CKD outcomes. Determinants of HRQOL as measured by the validated Kidney Disease Quality of Life questionnaire (KDQOL) and the Patient Health Questionnaire depression screener (PHQ-9) were assessed in a routine CKD patient sample, the Greifswald Approach to Individualized Medicine (GANI_MED) renal cohort (N = 160), including a wide range of self-reported data, sociodemographic and laboratory measures. Compared to the general population, CKD patients had lower HRQOL indices. Dialysis was associated with (1) low levels of physical functioning, (2) increased impairments by symptoms and problems, and (3) more effects and burden of kidney disease. HRQOL is seriously affected in CKD patients. However, impairments were found irrespective of eGFR decline and albuminuria. Rather, the comorbid conditions of depression and diabetes predicted a lower HRQOL (physical component score). Further studies should address whether recognizing and treating depression may not only improve HRQOL but also promote survival and lower hospitalization rates of CKD patients.

The nephrotic syndrome holds significant clinical importance and is characterized by a substantial protein loss in the urine. Damage to the glomerular basement membrane or podocytes frequently underlies renal protein loss. There is an increasing belief in the involvement of the complement system, a part of the innate immune system, in these conditions. Understanding the interactions between the complement system and glomerular structures continually evolves, challenging the traditional view of the blood–urine barrier as a passive filter. Clinical studies suggest that a precise inhibition of the complement system at various points may soon become feasible. However, a thorough understanding of current knowledge is imperative for planning future therapies in nephrotic glomerular diseases such as membranous glomerulopathy, membranoproliferative glomerulonephritis, lupus nephritis, focal segmental glomerulosclerosis, and minimal change disease. This review provides an overview of the complement system, its interactions with glomerular structures, and insights into specific glomerular diseases exhibiting a nephrotic course. Additionally, we explore new diagnostic tools and future therapeutic approaches.

At the beginning of life, there are no sex differences in fetal kidney growth, nephron endowment nor in the prevalence of low birth weight. In chronic kidney disease (CKD) in adults, however, significant sex- and gender-specific differences exist in diagnosis, progression, and management of CKD. In adult individuals, CKD is more prevalent in women, but CKD progression is faster in men; nevertheless, women have a higher life expectancy than men. A possible explanation for the enigmatic higher CKD prevalence in women may derive from the Brenner–Luyckx concept of hyperfiltration. Diseases that lead to hyperfiltration will lead to premature nephron loss and to a faster decline in glomerular filtration rate (GFR). This condition is predominantly seen in middle-aged men with a higher GFR, larger hypertrophied kidneys, and a higher prevalence of arterial hypertension, diabetes mellitus, smoking, and hypercholesterolemia compared to women. Thus, a high GFR may not be a good sign if it reflects hyperfiltration. Any GFR must be interpreted against the comorbidities of an individual. An individual may end up with a realistic GFR far below normal once hyperfiltration is stopped, for example, by a Sodium Glucose-Linked Transporter 2 (SGLT2) inhibitor. With regard to the management of CKD, women with CKD receive poorer healthcare compared to men with CKD. Women less frequently receive a CKD diagnosis, are less frequently referred to nephrology for co-management, less frequently undergo eGFR and albuminuria assessments, and are less likely to receive guideline-recommended treatments for CKD, such as angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers, and statins. Cardiovascular risk factors are less rigorously controlled in women with CKD compared to men with CKD. The causes for the poorer CKD care among women are to be found in gender rather than in sex. It is crucial to integrate assessments of sex and gender into both clinical routines and scientific reports. All studies should incorporate sex- and gender-specific analyses, and the evaluation of pre- and postmenopausal women should be conducted separately. The utilization of Gender Scores can help identify the impact of cultural, societal, and psychological factors on observed gender differences in ambulatory healthcare for those with CKD. Guidelines need to be sensitive to gender and emphasize the existing knowledge gaps regarding sex and gender differences in CKD healthcare. Urgent attention is required to substantially improve and ensure equitable healthcare for CKD across sexes and genders.