本研究針對肌少症與下泌尿道症狀（LUTS）之關聯性與盛行率進行系統性回顧與統合分析，從流行病學與臨床整合的角度切入，具有明確且實質的學術與臨床意義。肌少症與LUTS皆為高齡族群中高度盛行且影響功能狀態與生活品質的重要健康問題，兩者亦可能共享共同的病理生理基礎，包括慢性低度發炎、神經肌肉退化、自主神經功能失衡、活動量下降、睡眠品質惡化與整體衰弱（frailty）狀態。然而，過往文獻多為單一族群、小樣本或未調整混雜因子的橫斷研究，缺乏整體量化證據。本研究依循PRISMA與MOOSE指引，並完成PROSPERO註冊，系統性搜尋並納入25篇研究、共84,484名受試者，在方法學透明度與執行流程上具備相當嚴謹性。除計算整體pooled OR與盛行率外，作者進一步依不同肌少症診斷標準（AWGS、EWGSOP）、不同構成指標（低肌肉量LLM、低肌力LMS、低步行速度LGS、SARC-F篩檢陽性）、LUTS分型與族群場域（社區與機構住民）進行分層分析，並透過單變量meta-regression探討年齡、BMI、性別比例、WHO區域與偏倚風險等研究層級變項對效應值之影響，顯示研究設計不僅止於描述性統合，而是嘗試深入理解異質性來源與潛在效應修飾因子。

結果顯示肌少症與LUTS存在顯著關聯（pooled OR = 1.78），且整體LUTS盛行率高達43.2%，在使用AWGS標準、嚴重肌少症定義與機構照護族群中關聯性更為顯著，尤其SARC-F篩檢陽性者之OR達3.20，提示功能性衰弱與主觀功能障礙可能在LUTS發生機制中扮演重要角色。此結果具有臨床警示意義，意味著在高齡泌尿門診或長照機構中，肌少症與衰弱評估不應被忽略。然而，本研究亦揭示重要而值得深思的發現，即低肌力（LMS）與LUTS並未呈現顯著關聯（OR = 0.94），而低肌肉量與低步行速度則呈現顯著相關，這暗示單純肌力下降未必是關鍵因素，反而整體身體組成改變與功能性活動能力下降可能更具解釋力，亦可能代表LUTS與全身性衰弱狀態之關聯，而非單純骨骼肌力量對排尿功能的直接影響。這一結果在理論層面值得更深入討論，因其挑戰了「骨盆底肌力不足導致LUTS」的單一路徑假設。

儘管如此，本研究仍存在若干結構性限制。首先，納入研究多為橫斷式設計，缺乏時間序列資料，無法確認肌少症是否為LUTS之危險因子，或LUTS導致活動量下降、睡眠障礙與社交退縮進而加速肌少症形成，反向因果關係無法排除。其次，統合分析之異質性極高（I² > 90%），顯示研究間在LUTS定義、評估工具（問卷、臨床診斷、ICD碼）、肌少症切點、族群年齡層與性別比例等方面差異顯著，雖採用隨機效應模型並進行次群與meta-regression分析，但在如此高異質性情況下，pooled OR的穩定性與外部效度仍須審慎解讀。此外，LUTS本身為一高度異質性的症候群，涵蓋儲尿、排尿與排尿後症狀，其神經生理與解剖機轉並不一致，將其合併分析可能削弱生物學合理性與臨床精準度，未來若能針對特定亞型（如夜尿、OAB、逼尿肌低活動性或尿失禁）進行更細緻分析，將更有助於釐清機轉與臨床應用方向。

整體而言，本研究為目前關於肌少症與LUTS關聯性最具規模與分析深度之量化整合證據，成功建立兩大老年醫學重要議題之間的流行病學連結，具有假說生成與跨領域整合的價值。然而，其證據層級仍屬觀察性關聯階段，尚未達到因果推論或臨床決策改變之程度。未來研究需透過前瞻性世代研究、機轉導向研究及介入試驗（例如肌少症治療對LUTS改善之影響）進一步驗證方向性與生物學機制，同時推動診斷標準與症狀分型之標準化，以提升研究結果之臨床可轉譯性與政策應用價值。

Background and Objectives: Sarcopenia and lower urinary tract symptoms (LUTSs) are both prevalent among older adults and may share underlying pathophysiological mechanisms. However, their association has not been systematically quantified. This systematic review and meta-analysis aimed to evaluate the association between sarcopenia and LUTSs, including the pooled estimates of prevalence and odds ratios (ORs), and to explore the influence of diagnostic definitions and study-level factors. Materials and Methods: A comprehensive literature search was conducted using PubMed and Embase for studies published between 1 January 2000 and 26 April 2025. This study adhered to PRISMA and MOOSE guidelines and was registered in PROSPERO (CRD420251037459). Eligible observational studies reported LUTS prevalence or ORs in individuals with sarcopenia, low muscle strength (LMS), low lean mass (LLM), low gait speed (LGS), or sarcopenia risk identified by SARC-F (score ≥4). Pooled ORs and prevalence rates were calculated using a random-effects model. Subgroup analyses were performed based on sarcopenia definitions—Asian Working Group for Sarcopenia (AWGS) and European Working Group on Sarcopenia in Older People (EWGSOP)—as well as LUTS subtypes and diagnostic components. Univariate meta-regression assessed associations with age, BMI, sex distribution, WHO region, and risk of bias. Results: Twenty-five studies comprising 84,484 participants were included. Sarcopenia was significantly associated with LUTSs (pooled OR = 1.78; 95% CI: 1.29–2.45; p < 0.001), with a pooled LUTS prevalence of 43.2% (95% CI: 26.9–61.0%). Stronger associations were observed in studies using AWGS diagnostic criteria (OR = 2.24; 95% CI: 1.41–3.56; p = 0.001), in those evaluating severe sarcopenia (OR = 1.66; 95% CI: 1.03–2.68; p = 0.038), and in institutionalized populations (OR = 3.68; 95% CI: 2.18–6.24; p < 0.001) compared to community-dwelling populations (OR = 1.43; 95% CI: 1.06–1.92; p = 0.018). Sarcopenia risk identified by SARC-F (score ≥4) showed the strongest association with LUTSs (OR = 3.20; 95% CI: 1.92–5.33; p < 0.001). Significant associations were also found for LLM (OR = 1.52; 95% CI: 1.19–1.95; p = 0.001) and LGS (OR = 1.37; 95% CI: 1.06–1.76; p = 0.015), but not for LMS (OR = 0.94; 95% CI: 0.47–1.89; p = 0.871). Exploratory analyses comparing LLM diagnostic modalities—including standardized criteria (ASMI, ASM/BMI), imaging-based methods (SMI, PMA), and surrogate measures (calf circumference)—revealed no significant differences (all p > 0.05). Heterogeneity was high (I2 > 90%). Egger’s test indicated no evidence of publication bias (p = 0.838), and trim-and-fill analysis did not affect the pooled estimates. Conclusions: Sarcopenia—particularly in its severe forms—is significantly associated with LUTSs. Additionally, individuals who screened positive for sarcopenia using the SARC-F tool demonstrated a heightened risk of LUTSs. Subgroup analyses revealed a stronger association in institutionalized populations, suggesting that care setting may modify risk. These findings underscore the importance of assessing muscle health in older adults with urinary symptoms. Standardization of diagnostic criteria and longitudinal studies are needed to clarify causality and guide targeted interventions.